d3.js

(function(){if (!Date.now) Date.now = function() {
    return +new Date;
  };
  try {
    document.createElement("div").style.setProperty("opacity", 0, "");
  } catch (error) {
    var d3_style_prototype = CSSStyleDeclaration.prototype,
        d3_style_setProperty = d3_style_prototype.setProperty;
    d3_style_prototype.setProperty = function(name, value, priority) {
      d3_style_setProperty.call(this, name, value + "", priority);
    };
  }
  d3 = {version: "2.8.1"}; // semver
  function d3_class(ctor, properties) {
    try {
      for (var key in properties) {
        Object.defineProperty(ctor.prototype, key, {
          value: properties[key],
          enumerable: false
        });
      }
    } catch (e) {
      ctor.prototype = properties;
    }
  }
  var d3_array = d3_arraySlice; // conversion for NodeLists
  
  function d3_arrayCopy(pseudoarray) {
    var i = -1, n = pseudoarray.length, array = [];
    while (++i < n) array.push(pseudoarray[i]);
    return array;
  }
  
  function d3_arraySlice(pseudoarray) {
    return Array.prototype.slice.call(pseudoarray);
  }
  
  try {
    d3_array(document.documentElement.childNodes)[0].nodeType;
  } catch(e) {
    d3_array = d3_arrayCopy;
  }
  
  var d3_arraySubclass = [].__proto__?
  
  // Until ECMAScript supports array subclassing, prototype injection works well.
  function(array, prototype) {
    array.__proto__ = prototype;
  }:
  
  // And if your browser doesn't support __proto__, we'll use direct extension.
  function(array, prototype) {
    for (var property in prototype) array[property] = prototype[property];
  };
  d3.map = function(object) {
    var map = new d3_Map;
    for (var key in object) map.set(key, object[key]);
    return map;
  };
  
  function d3_Map() {}
  
  d3_class(d3_Map, {
    has: function(key) {
      return d3_map_prefix + key in this;
    },
    get: function(key) {
      return this[d3_map_prefix + key];
    },
    set: function(key, value) {
      return this[d3_map_prefix + key] = value;
    },
    remove: function(key) {
      key = d3_map_prefix + key;
      return key in this && delete this[key];
    },
    keys: function() {
      var keys = [];
      this.forEach(function(key) { keys.push(key); });
      return keys;
    },
    values: function() {
      var values = [];
      this.forEach(function(key, value) { values.push(value); });
      return values;
    },
    entries: function() {
      var entries = [];
      this.forEach(function(key, value) { entries.push({key: key, value: value}); });
      return entries;
    },
    forEach: function(f) {
      for (var key in this) {
        if (key.charCodeAt(0) === d3_map_prefixCode) {
          f.call(this, key.substring(1), this[key]);
        }
      }
    }
  });
  
  var d3_map_prefix = "\0", // prevent collision with built-ins
      d3_map_prefixCode = d3_map_prefix.charCodeAt(0);
  function d3_this() {
    return this;
  }
  d3.functor = function(v) {
    return typeof v === "function" ? v : function() { return v; };
  };
  // Copies a variable number of methods from source to target.
  d3.rebind = function(target, source) {
    var i = 1, n = arguments.length, method;
    while (++i < n) target[method = arguments[i]] = d3_rebind(target, source, source[method]);
    return target;
  };
  
  // Method is assumed to be a standard D3 getter-setter:
  // If passed with no arguments, gets the value.
  // If passed with arguments, sets the value and returns the target.
  function d3_rebind(target, source, method) {
    return function() {
      var value = method.apply(source, arguments);
      return arguments.length ? target : value;
    };
  }
  d3.ascending = function(a, b) {
    return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
  };
  d3.descending = function(a, b) {
    return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
  };
  d3.mean = function(array, f) {
    var n = array.length,
        a,
        m = 0,
        i = -1,
        j = 0;
    if (arguments.length === 1) {
      while (++i < n) if (d3_number(a = array[i])) m += (a - m) / ++j;
    } else {
      while (++i < n) if (d3_number(a = f.call(array, array[i], i))) m += (a - m) / ++j;
    }
    return j ? m : undefined;
  };
  d3.median = function(array, f) {
    if (arguments.length > 1) array = array.map(f);
    array = array.filter(d3_number);
    return array.length ? d3.quantile(array.sort(d3.ascending), .5) : undefined;
  };
  d3.min = function(array, f) {
    var i = -1,
        n = array.length,
        a,
        b;
    if (arguments.length === 1) {
      while (++i < n && ((a = array[i]) == null || a != a)) a = undefined;
      while (++i < n) if ((b = array[i]) != null && a > b) a = b;
    } else {
      while (++i < n && ((a = f.call(array, array[i], i)) == null || a != a)) a = undefined;
      while (++i < n) if ((b = f.call(array, array[i], i)) != null && a > b) a = b;
    }
    return a;
  };
  d3.max = function(array, f) {
    var i = -1,
        n = array.length,
        a,
        b;
    if (arguments.length === 1) {
      while (++i < n && ((a = array[i]) == null || a != a)) a = undefined;
      while (++i < n) if ((b = array[i]) != null && b > a) a = b;
    } else {
      while (++i < n && ((a = f.call(array, array[i], i)) == null || a != a)) a = undefined;
      while (++i < n) if ((b = f.call(array, array[i], i)) != null && b > a) a = b;
    }
    return a;
  };
  d3.extent = function(array, f) {
    var i = -1,
        n = array.length,
        a,
        b,
        c;
    if (arguments.length === 1) {
      while (++i < n && ((a = c = array[i]) == null || a != a)) a = c = undefined;
      while (++i < n) if ((b = array[i]) != null) {
        if (a > b) a = b;
        if (c < b) c = b;
      }
    } else {
      while (++i < n && ((a = c = f.call(array, array[i], i)) == null || a != a)) a = undefined;
      while (++i < n) if ((b = f.call(array, array[i], i)) != null) {
        if (a > b) a = b;
        if (c < b) c = b;
      }
    }
    return [a, c];
  };
  d3.random = {
    normal: function(mean, deviation) {
      if (arguments.length < 2) deviation = 1;
      if (arguments.length < 1) mean = 0;
      return function() {
        var x, y, r;
        do {
          x = Math.random() * 2 - 1;
          y = Math.random() * 2 - 1;
          r = x * x + y * y;
        } while (!r || r > 1);
        return mean + deviation * x * Math.sqrt(-2 * Math.log(r) / r);
      };
    }
  };
  function d3_number(x) {
    return x != null && !isNaN(x);
  }
  d3.sum = function(array, f) {
    var s = 0,
        n = array.length,
        a,
        i = -1;
  
    if (arguments.length === 1) {
      while (++i < n) if (!isNaN(a = +array[i])) s += a;
    } else {
      while (++i < n) if (!isNaN(a = +f.call(array, array[i], i))) s += a;
    }
  
    return s;
  };
  // R-7 per <http://en.wikipedia.org/wiki/Quantile>
  d3.quantile = function(values, p) {
    var H = (values.length - 1) * p + 1,
        h = Math.floor(H),
        v = values[h - 1],
        e = H - h;
    return e ? v + e * (values[h] - v) : v;
  };
  d3.transpose = function(matrix) {
    return d3.zip.apply(d3, matrix);
  };
  d3.zip = function() {
    if (!(n = arguments.length)) return [];
    for (var i = -1, m = d3.min(arguments, d3_zipLength), zips = new Array(m); ++i < m;) {
      for (var j = -1, n, zip = zips[i] = new Array(n); ++j < n;) {
        zip[j] = arguments[j][i];
      }
    }
    return zips;
  };
  
  function d3_zipLength(d) {
    return d.length;
  }
  d3.bisector = function(f) {
    return {
      left: function(a, x, lo, hi) {
        if (arguments.length < 3) lo = 0;
        if (arguments.length < 4) hi = a.length;
        while (lo < hi) {
          var mid = lo + hi >> 1;
          if (f.call(a, a[mid], mid) < x) lo = mid + 1;
          else hi = mid;
        }
        return lo;
      },
      right: function(a, x, lo, hi) {
        if (arguments.length < 3) lo = 0;
        if (arguments.length < 4) hi = a.length;
        while (lo < hi) {
          var mid = lo + hi >> 1;
          if (x < f.call(a, a[mid], mid)) hi = mid;
          else lo = mid + 1;
        }
        return lo;
      }
    };
  };
  
  var d3_bisector = d3.bisector(function(d) { return d; });
  d3.bisectLeft = d3_bisector.left;
  d3.bisect = d3.bisectRight = d3_bisector.right;
  d3.first = function(array, f) {
    var i = 0,
        n = array.length,
        a = array[0],
        b;
    if (arguments.length === 1) f = d3.ascending;
    while (++i < n) {
      if (f.call(array, a, b = array[i]) > 0) {
        a = b;
      }
    }
    return a;
  };
  d3.last = function(array, f) {
    var i = 0,
        n = array.length,
        a = array[0],
        b;
    if (arguments.length === 1) f = d3.ascending;
    while (++i < n) {
      if (f.call(array, a, b = array[i]) <= 0) {
        a = b;
      }
    }
    return a;
  };
  d3.nest = function() {
    var nest = {},
        keys = [],
        sortKeys = [],
        sortValues,
        rollup;
  
    function map(array, depth) {
      if (depth >= keys.length) return rollup
          ? rollup.call(nest, array) : (sortValues
          ? array.sort(sortValues)
          : array);
  
      var i = -1,
          n = array.length,
          key = keys[depth++],
          keyValue,
          object,
          valuesByKey = new d3_Map,
          values,
          o = {};
  
      while (++i < n) {
        if (values = valuesByKey.get(keyValue = key(object = array[i]))) {
          values.push(object);
        } else {
          valuesByKey.set(keyValue, [object]);
        }
      }
  
      valuesByKey.forEach(function(keyValue) {
        o[keyValue] = map(valuesByKey.get(keyValue), depth);
      });
  
      return o;
    }
  
    function entries(map, depth) {
      if (depth >= keys.length) return map;
  
      var a = [],
          sortKey = sortKeys[depth++],
          key;
  
      for (key in map) {
        a.push({key: key, values: entries(map[key], depth)});
      }
  
      if (sortKey) a.sort(function(a, b) {
        return sortKey(a.key, b.key);
      });
  
      return a;
    }
  
    nest.map = function(array) {
      return map(array, 0);
    };
  
    nest.entries = function(array) {
      return entries(map(array, 0), 0);
    };
  
    nest.key = function(d) {
      keys.push(d);
      return nest;
    };
  
    // Specifies the order for the most-recently specified key.
    // Note: only applies to entries. Map keys are unordered!
    nest.sortKeys = function(order) {
      sortKeys[keys.length - 1] = order;
      return nest;
    };
  
    // Specifies the order for leaf values.
    // Applies to both maps and entries array.
    nest.sortValues = function(order) {
      sortValues = order;
      return nest;
    };
  
    nest.rollup = function(f) {
      rollup = f;
      return nest;
    };
  
    return nest;
  };
  d3.keys = function(map) {
    var keys = [];
    for (var key in map) keys.push(key);
    return keys;
  };
  d3.values = function(map) {
    var values = [];
    for (var key in map) values.push(map[key]);
    return values;
  };
  d3.entries = function(map) {
    var entries = [];
    for (var key in map) entries.push({key: key, value: map[key]});
    return entries;
  };
  d3.permute = function(array, indexes) {
    var permutes = [],
        i = -1,
        n = indexes.length;
    while (++i < n) permutes[i] = array[indexes[i]];
    return permutes;
  };
  d3.merge = function(arrays) {
    return Array.prototype.concat.apply([], arrays);
  };
  d3.split = function(array, f) {
    var arrays = [],
        values = [],
        value,
        i = -1,
        n = array.length;
    if (arguments.length < 2) f = d3_splitter;
    while (++i < n) {
      if (f.call(values, value = array[i], i)) {
        values = [];
      } else {
        if (!values.length) arrays.push(values);
        values.push(value);
      }
    }
    return arrays;
  };
  
  function d3_splitter(d) {
    return d == null;
  }
  function d3_collapse(s) {
    return s.replace(/(^\s+)|(\s+$)/g, "").replace(/\s+/g, " ");
  }
  d3.range = function(start, stop, step) {
    if (arguments.length < 3) {
      step = 1;
      if (arguments.length < 2) {
        stop = start;
        start = 0;
      }
    }
    if ((stop - start) / step === Infinity) throw new Error("infinite range");
    var range = [],
         k = d3_range_integerScale(Math.abs(step)),
         i = -1,
         j;
    start *= k, stop *= k, step *= k;
    if (step < 0) while ((j = start + step * ++i) > stop) range.push(j / k);
    else while ((j = start + step * ++i) < stop) range.push(j / k);
    return range;
  };
  
  function d3_range_integerScale(x) {
    var k = 1;
    while (x * k % 1) k *= 10;
    return k;
  }
  d3.requote = function(s) {
    return s.replace(d3_requote_re, "\\$&");
  };
  
  var d3_requote_re = /[\\\^\$\*\+\?\|\[\]\(\)\.\{\}]/g;
  d3.round = function(x, n) {
    return n
        ? Math.round(x * (n = Math.pow(10, n))) / n
        : Math.round(x);
  };
  d3.xhr = function(url, mime, callback) {
    var req = new XMLHttpRequest;
    if (arguments.length < 3) callback = mime, mime = null;
    else if (mime && req.overrideMimeType) req.overrideMimeType(mime);
    req.open("GET", url, true);
    if (mime) req.setRequestHeader("Accept", mime);
    req.onreadystatechange = function() {
      if (req.readyState === 4) callback(req.status < 300 ? req : null);
    };
    req.send(null);
  };
  d3.text = function(url, mime, callback) {
    function ready(req) {
      callback(req && req.responseText);
    }
    if (arguments.length < 3) {
      callback = mime;
      mime = null;
    }
    d3.xhr(url, mime, ready);
  };
  d3.json = function(url, callback) {
    d3.text(url, "application/json", function(text) {
      callback(text ? JSON.parse(text) : null);
    });
  };
  d3.html = function(url, callback) {
    d3.text(url, "text/html", function(text) {
      if (text != null) { // Treat empty string as valid HTML.
        var range = document.createRange();
        range.selectNode(document.body);
        text = range.createContextualFragment(text);
      }
      callback(text);
    });
  };
  d3.xml = function(url, mime, callback) {
    function ready(req) {
      callback(req && req.responseXML);
    }
    if (arguments.length < 3) {
      callback = mime;
      mime = null;
    }
    d3.xhr(url, mime, ready);
  };
  var d3_nsPrefix = {
    svg: "http://www.w3.org/2000/svg",
    xhtml: "http://www.w3.org/1999/xhtml",
    xlink: "http://www.w3.org/1999/xlink",
    xml: "http://www.w3.org/XML/1998/namespace",
    xmlns: "http://www.w3.org/2000/xmlns/"
  };
  
  d3.ns = {
    prefix: d3_nsPrefix,
    qualify: function(name) {
      var i = name.indexOf(":"),
          prefix = name;
      if (i >= 0) {
        prefix = name.substring(0, i);
        name = name.substring(i + 1);
      }
      return d3_nsPrefix.hasOwnProperty(prefix)
          ? {space: d3_nsPrefix[prefix], local: name}
          : name;
    }
  };
  d3.dispatch = function() {
    var dispatch = new d3_dispatch,
        i = -1,
        n = arguments.length;
    while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
    return dispatch;
  };
  
  function d3_dispatch() {}
  
  d3_dispatch.prototype.on = function(type, listener) {
    var i = type.indexOf("."),
        name = "";
  
    // Extract optional namespace, e.g., "click.foo"
    if (i > 0) {
      name = type.substring(i + 1);
      type = type.substring(0, i);
    }
  
    return arguments.length < 2
        ? this[type].on(name)
        : this[type].on(name, listener);
  };
  
  function d3_dispatch_event(dispatch) {
    var listeners = [],
        listenerByName = new d3_Map;
  
    function event() {
      var z = listeners, // defensive reference
          i = -1,
          n = z.length,
          l;
      while (++i < n) if (l = z[i].on) l.apply(this, arguments);
      return dispatch;
    }
  
    event.on = function(name, listener) {
      var l = listenerByName.get(name),
          i;
  
      // return the current listener, if any
      if (arguments.length < 2) return l && l.on;
  
      // remove the old listener, if any (with copy-on-write)
      if (l) {
        l.on = null;
        listeners = listeners.slice(0, i = listeners.indexOf(l)).concat(listeners.slice(i + 1));
        listenerByName.remove(name);
      }
  
      // add the new listener, if any
      if (listener) listeners.push(listenerByName.set(name, {on: listener}));
  
      return dispatch;
    };
  
    return event;
  }
  // TODO align
  d3.format = function(specifier) {
    var match = d3_format_re.exec(specifier),
        fill = match[1] || " ",
        sign = match[3] || "",
        zfill = match[5],
        width = +match[6],
        comma = match[7],
        precision = match[8],
        type = match[9],
        scale = 1,
        suffix = "",
        integer = false;
  
    if (precision) precision = +precision.substring(1);
  
    if (zfill) {
      fill = "0"; // TODO align = "=";
      if (comma) width -= Math.floor((width - 1) / 4);
    }
  
    switch (type) {
      case "n": comma = true; type = "g"; break;
      case "%": scale = 100; suffix = "%"; type = "f"; break;
      case "p": scale = 100; suffix = "%"; type = "r"; break;
      case "d": integer = true; precision = 0; break;
      case "s": scale = -1; type = "r"; break;
    }
  
    // If no precision is specified for r, fallback to general notation.
    if (type == "r" && !precision) type = "g";
  
    type = d3_format_types.get(type) || d3_format_typeDefault;
  
    return function(value) {
  
      // Return the empty string for floats formatted as ints.
      if (integer && (value % 1)) return "";
  
      // Convert negative to positive, and record the sign prefix.
      var negative = (value < 0) && (value = -value) ? "\u2212" : sign;
  
      // Apply the scale, computing it from the value's exponent for si format.
      if (scale < 0) {
        var prefix = d3.formatPrefix(value, precision);
        value *= prefix.scale;
        suffix = prefix.symbol;
      } else {
        value *= scale;
      }
  
      // Convert to the desired precision.
      value = type(value, precision);
  
      // If the fill character is 0, the sign and group is applied after the fill.
      if (zfill) {
        var length = value.length + negative.length;
        if (length < width) value = new Array(width - length + 1).join(fill) + value;
        if (comma) value = d3_format_group(value);
        value = negative + value;
      }
  
      // Otherwise (e.g., space-filling), the sign and group is applied before.
      else {
        if (comma) value = d3_format_group(value);
        value = negative + value;
        var length = value.length;
        if (length < width) value = new Array(width - length + 1).join(fill) + value;
      }
  
      return value + suffix;
    };
  };
  
  // [[fill]align][sign][#][0][width][,][.precision][type]
  var d3_format_re = /(?:([^{])?([<>=^]))?([+\- ])?(#)?(0)?([0-9]+)?(,)?(\.[0-9]+)?([a-zA-Z%])?/;
  
  var d3_format_types = d3.map({
    g: function(x, p) { return x.toPrecision(p); },
    e: function(x, p) { return x.toExponential(p); },
    f: function(x, p) { return x.toFixed(p); },
    r: function(x, p) { return d3.round(x, p = d3_format_precision(x, p)).toFixed(Math.max(0, Math.min(20, p))); }
  });
  
  function d3_format_precision(x, p) {
    return p - (x ? 1 + Math.floor(Math.log(x + Math.pow(10, 1 + Math.floor(Math.log(x) / Math.LN10) - p)) / Math.LN10) : 1);
  }
  
  function d3_format_typeDefault(x) {
    return x + "";
  }
  
  // Apply comma grouping for thousands.
  function d3_format_group(value) {
    var i = value.lastIndexOf("."),
        f = i >= 0 ? value.substring(i) : (i = value.length, ""),
        t = [];
    while (i > 0) t.push(value.substring(i -= 3, i + 3));
    return t.reverse().join(",") + f;
  }
  var d3_formatPrefixes = ["y","z","a","f","p","n","μ","m","","k","M","G","T","P","E","Z","Y"].map(d3_formatPrefix);
  
  d3.formatPrefix = function(value, precision) {
    var i = 0;
    if (value) {
      if (value < 0) value *= -1;
      if (precision) value = d3.round(value, d3_format_precision(value, precision));
      i = 1 + Math.floor(1e-12 + Math.log(value) / Math.LN10);
      i = Math.max(-24, Math.min(24, Math.floor((i <= 0 ? i + 1 : i - 1) / 3) * 3));
    }
    return d3_formatPrefixes[8 + i / 3];
  };
  
  function d3_formatPrefix(d, i) {
    return {
      scale: Math.pow(10, (8 - i) * 3),
      symbol: d
    };
  }
  
  /*
   * TERMS OF USE - EASING EQUATIONS
   *
   * Open source under the BSD License.
   *
   * Copyright 2001 Robert Penner
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * - Redistributions of source code must retain the above copyright notice, this
   *   list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   *
   * - Neither the name of the author nor the names of contributors may be used to
   *   endorse or promote products derived from this software without specific
   *   prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  var d3_ease_quad = d3_ease_poly(2),
      d3_ease_cubic = d3_ease_poly(3),
      d3_ease_default = function() { return d3_ease_identity; };
  
  var d3_ease = d3.map({
    linear: d3_ease_default,
    poly: d3_ease_poly,
    quad: function() { return d3_ease_quad; },
    cubic: function() { return d3_ease_cubic; },
    sin: function() { return d3_ease_sin; },
    exp: function() { return d3_ease_exp; },
    circle: function() { return d3_ease_circle; },
    elastic: d3_ease_elastic,
    back: d3_ease_back,
    bounce: function() { return d3_ease_bounce; }
  });
  
  var d3_ease_mode = d3.map({
    "in": d3_ease_identity,
    "out": d3_ease_reverse,
    "in-out": d3_ease_reflect,
    "out-in": function(f) { return d3_ease_reflect(d3_ease_reverse(f)); }
  });
  
  d3.ease = function(name) {
    var i = name.indexOf("-"),
        t = i >= 0 ? name.substring(0, i) : name,
        m = i >= 0 ? name.substring(i + 1) : "in";
    t = d3_ease.get(t) || d3_ease_default;
    m = d3_ease_mode.get(m) || d3_ease_identity;
    return d3_ease_clamp(m(t.apply(null, Array.prototype.slice.call(arguments, 1))));
  };
  
  function d3_ease_clamp(f) {
    return function(t) {
      return t <= 0 ? 0 : t >= 1 ? 1 : f(t);
    };
  }
  
  function d3_ease_reverse(f) {
    return function(t) {
      return 1 - f(1 - t);
    };
  }
  
  function d3_ease_reflect(f) {
    return function(t) {
      return .5 * (t < .5 ? f(2 * t) : (2 - f(2 - 2 * t)));
    };
  }
  
  function d3_ease_identity(t) {
    return t;
  }
  
  function d3_ease_poly(e) {
    return function(t) {
      return Math.pow(t, e);
    };
  }
  
  function d3_ease_sin(t) {
    return 1 - Math.cos(t * Math.PI / 2);
  }
  
  function d3_ease_exp(t) {
    return Math.pow(2, 10 * (t - 1));
  }
  
  function d3_ease_circle(t) {
    return 1 - Math.sqrt(1 - t * t);
  }
  
  function d3_ease_elastic(a, p) {
    var s;
    if (arguments.length < 2) p = 0.45;
    if (arguments.length < 1) { a = 1; s = p / 4; }
    else s = p / (2 * Math.PI) * Math.asin(1 / a);
    return function(t) {
      return 1 + a * Math.pow(2, 10 * -t) * Math.sin((t - s) * 2 * Math.PI / p);
    };
  }
  
  function d3_ease_back(s) {
    if (!s) s = 1.70158;
    return function(t) {
      return t * t * ((s + 1) * t - s);
    };
  }
  
  function d3_ease_bounce(t) {
    return t < 1 / 2.75 ? 7.5625 * t * t
        : t < 2 / 2.75 ? 7.5625 * (t -= 1.5 / 2.75) * t + .75
        : t < 2.5 / 2.75 ? 7.5625 * (t -= 2.25 / 2.75) * t + .9375
        : 7.5625 * (t -= 2.625 / 2.75) * t + .984375;
  }
  d3.event = null;
  
  function d3_eventCancel() {
    d3.event.stopPropagation();
    d3.event.preventDefault();
  }
  
  function d3_eventSource() {
    var e = d3.event, s;
    while (s = e.sourceEvent) e = s;
    return e;
  }
  
  // Like d3.dispatch, but for custom events abstracting native UI events. These
  // events have a target component (such as a brush), a target element (such as
  // the svg:g element containing the brush) and the standard arguments `d` (the
  // target element's data) and `i` (the selection index of the target element).
  function d3_eventDispatch(target) {
    var dispatch = new d3_dispatch,
        i = 0,
        n = arguments.length;
  
    while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
  
    // Creates a dispatch context for the specified `thiz` (typically, the target
    // DOM element that received the source event) and `argumentz` (typically, the
    // data `d` and index `i` of the target element). The returned function can be
    // used to dispatch an event to any registered listeners; the function takes a
    // single argument as input, being the event to dispatch. The event must have
    // a "type" attribute which corresponds to a type registered in the
    // constructor. This context will automatically populate the "sourceEvent" and
    // "target" attributes of the event, as well as setting the `d3.event` global
    // for the duration of the notification.
    dispatch.of = function(thiz, argumentz) {
      return function(e1) {
        try {
          var e0 =
          e1.sourceEvent = d3.event;
          e1.target = target;
          d3.event = e1;
          dispatch[e1.type].apply(thiz, argumentz);
        } finally {
          d3.event = e0;
        }
      };
    };
  
    return dispatch;
  }
  d3.interpolate = function(a, b) {
    var i = d3.interpolators.length, f;
    while (--i >= 0 && !(f = d3.interpolators[i](a, b)));
    return f;
  };
  
  d3.interpolateNumber = function(a, b) {
    b -= a;
    return function(t) { return a + b * t; };
  };
  
  d3.interpolateRound = function(a, b) {
    b -= a;
    return function(t) { return Math.round(a + b * t); };
  };
  
  d3.interpolateString = function(a, b) {
    var m, // current match
        i, // current index
        j, // current index (for coallescing)
        s0 = 0, // start index of current string prefix
        s1 = 0, // end index of current string prefix
        s = [], // string constants and placeholders
        q = [], // number interpolators
        n, // q.length
        o;
  
    // Reset our regular expression!
    d3_interpolate_number.lastIndex = 0;
  
    // Find all numbers in b.
    for (i = 0; m = d3_interpolate_number.exec(b); ++i) {
      if (m.index) s.push(b.substring(s0, s1 = m.index));
      q.push({i: s.length, x: m[0]});
      s.push(null);
      s0 = d3_interpolate_number.lastIndex;
    }
    if (s0 < b.length) s.push(b.substring(s0));
  
    // Find all numbers in a.
    for (i = 0, n = q.length; (m = d3_interpolate_number.exec(a)) && i < n; ++i) {
      o = q[i];
      if (o.x == m[0]) { // The numbers match, so coallesce.
        if (o.i) {
          if (s[o.i + 1] == null) { // This match is followed by another number.
            s[o.i - 1] += o.x;
            s.splice(o.i, 1);
            for (j = i + 1; j < n; ++j) q[j].i--;
          } else { // This match is followed by a string, so coallesce twice.
            s[o.i - 1] += o.x + s[o.i + 1];
            s.splice(o.i, 2);
            for (j = i + 1; j < n; ++j) q[j].i -= 2;
          }
        } else {
            if (s[o.i + 1] == null) { // This match is followed by another number.
            s[o.i] = o.x;
          } else { // This match is followed by a string, so coallesce twice.
            s[o.i] = o.x + s[o.i + 1];
            s.splice(o.i + 1, 1);
            for (j = i + 1; j < n; ++j) q[j].i--;
          }
        }
        q.splice(i, 1);
        n--;
        i--;
      } else {
        o.x = d3.interpolateNumber(parseFloat(m[0]), parseFloat(o.x));
      }
    }
  
    // Remove any numbers in b not found in a.
    while (i < n) {
      o = q.pop();
      if (s[o.i + 1] == null) { // This match is followed by another number.
        s[o.i] = o.x;
      } else { // This match is followed by a string, so coallesce twice.
        s[o.i] = o.x + s[o.i + 1];
        s.splice(o.i + 1, 1);
      }
      n--;
    }
  
    // Special optimization for only a single match.
    if (s.length === 1) {
      return s[0] == null ? q[0].x : function() { return b; };
    }
  
    // Otherwise, interpolate each of the numbers and rejoin the string.
    return function(t) {
      for (i = 0; i < n; ++i) s[(o = q[i]).i] = o.x(t);
      return s.join("");
    };
  };
  
  d3.interpolateTransform = function(a, b) {
    var s = [], // string constants and placeholders
        q = [], // number interpolators
        n,
        A = d3.transform(a),
        B = d3.transform(b),
        ta = A.translate,
        tb = B.translate,
        ra = A.rotate,
        rb = B.rotate,
        wa = A.skew,
        wb = B.skew,
        ka = A.scale,
        kb = B.scale;
  
    if (ta[0] != tb[0] || ta[1] != tb[1]) {
      s.push("translate(", null, ",", null, ")");
      q.push({i: 1, x: d3.interpolateNumber(ta[0], tb[0])}, {i: 3, x: d3.interpolateNumber(ta[1], tb[1])});
    } else if (tb[0] || tb[1]) {
      s.push("translate(" + tb + ")");
    } else {
      s.push("");
    }
  
    if (ra != rb) {
      q.push({i: s.push(s.pop() + "rotate(", null, ")") - 2, x: d3.interpolateNumber(ra, rb)});
    } else if (rb) {
      s.push(s.pop() + "rotate(" + rb + ")");
    }
  
    if (wa != wb) {
      q.push({i: s.push(s.pop() + "skewX(", null, ")") - 2, x: d3.interpolateNumber(wa, wb)});
    } else if (wb) {
      s.push(s.pop() + "skewX(" + wb + ")");
    }
  
    if (ka[0] != kb[0] || ka[1] != kb[1]) {
      n = s.push(s.pop() + "scale(", null, ",", null, ")");
      q.push({i: n - 4, x: d3.interpolateNumber(ka[0], kb[0])}, {i: n - 2, x: d3.interpolateNumber(ka[1], kb[1])});
    } else if (kb[0] != 1 || kb[1] != 1) {
      s.push(s.pop() + "scale(" + kb + ")");
    }
  
    n = q.length;
    return function(t) {
      var i = -1, o;
      while (++i < n) s[(o = q[i]).i] = o.x(t);
      return s.join("");
    };
  };
  
  d3.interpolateRgb = function(a, b) {
    a = d3.rgb(a);
    b = d3.rgb(b);
    var ar = a.r,
        ag = a.g,
        ab = a.b,
        br = b.r - ar,
        bg = b.g - ag,
        bb = b.b - ab;
    return function(t) {
      return "#"
          + d3_rgb_hex(Math.round(ar + br * t))
          + d3_rgb_hex(Math.round(ag + bg * t))
          + d3_rgb_hex(Math.round(ab + bb * t));
    };
  };
  
  // interpolates HSL space, but outputs RGB string (for compatibility)
  d3.interpolateHsl = function(a, b) {
    a = d3.hsl(a);
    b = d3.hsl(b);
    var h0 = a.h,
        s0 = a.s,
        l0 = a.l,
        h1 = b.h - h0,
        s1 = b.s - s0,
        l1 = b.l - l0;
    return function(t) {
      return d3_hsl_rgb(h0 + h1 * t, s0 + s1 * t, l0 + l1 * t).toString();
    };
  };
  
  d3.interpolateArray = function(a, b) {
    var x = [],
        c = [],
        na = a.length,
        nb = b.length,
        n0 = Math.min(a.length, b.length),
        i;
    for (i = 0; i < n0; ++i) x.push(d3.interpolate(a[i], b[i]));
    for (; i < na; ++i) c[i] = a[i];
    for (; i < nb; ++i) c[i] = b[i];
    return function(t) {
      for (i = 0; i < n0; ++i) c[i] = x[i](t);
      return c;
    };
  };
  
  d3.interpolateObject = function(a, b) {
    var i = {},
        c = {},
        k;
    for (k in a) {
      if (k in b) {
        i[k] = d3_interpolateByName(k)(a[k], b[k]);
      } else {
        c[k] = a[k];
      }
    }
    for (k in b) {
      if (!(k in a)) {
        c[k] = b[k];
      }
    }
    return function(t) {
      for (k in i) c[k] = i[k](t);
      return c;
    };
  }
  
  var d3_interpolate_number = /[-+]?(?:\d*\.?\d+)(?:[eE][-+]?\d+)?/g;
  
  function d3_interpolateByName(n) {
    return n == "transform"
        ? d3.interpolateTransform
        : d3.interpolate;
  }
  
  d3.interpolators = [
    d3.interpolateObject,
    function(a, b) { return (b instanceof Array) && d3.interpolateArray(a, b); },
    function(a, b) { return (typeof a === "string" || typeof b === "string") && d3.interpolateString(a + "", b + ""); },
    function(a, b) { return (typeof b === "string" ? d3_rgb_names.has(b) || /^(#|rgb\(|hsl\()/.test(b) : b instanceof d3_Rgb || b instanceof d3_Hsl) && d3.interpolateRgb(a, b); },
    function(a, b) { return !isNaN(a = +a) && !isNaN(b = +b) && d3.interpolateNumber(a, b); }
  ];
  function d3_uninterpolateNumber(a, b) {
    b = b - (a = +a) ? 1 / (b - a) : 0;
    return function(x) { return (x - a) * b; };
  }
  
  function d3_uninterpolateClamp(a, b) {
    b = b - (a = +a) ? 1 / (b - a) : 0;
    return function(x) { return Math.max(0, Math.min(1, (x - a) * b)); };
  }
  d3.rgb = function(r, g, b) {
    return arguments.length === 1
        ? (r instanceof d3_Rgb ? d3_rgb(r.r, r.g, r.b)
        : d3_rgb_parse("" + r, d3_rgb, d3_hsl_rgb))
        : d3_rgb(~~r, ~~g, ~~b);
  };
  
  function d3_rgb(r, g, b) {
    return new d3_Rgb(r, g, b);
  }
  
  function d3_Rgb(r, g, b) {
    this.r = r;
    this.g = g;
    this.b = b;
  }
  
  d3_Rgb.prototype.brighter = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    var r = this.r,
        g = this.g,
        b = this.b,
        i = 30;
    if (!r && !g && !b) return d3_rgb(i, i, i);
    if (r && r < i) r = i;
    if (g && g < i) g = i;
    if (b && b < i) b = i;
    return d3_rgb(
        Math.min(255, Math.floor(r / k)),
        Math.min(255, Math.floor(g / k)),
        Math.min(255, Math.floor(b / k)));
  };
  
  d3_Rgb.prototype.darker = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_rgb(
        Math.floor(k * this.r),
        Math.floor(k * this.g),
        Math.floor(k * this.b));
  };
  
  d3_Rgb.prototype.hsl = function() {
    return d3_rgb_hsl(this.r, this.g, this.b);
  };
  
  d3_Rgb.prototype.toString = function() {
    return "#" + d3_rgb_hex(this.r) + d3_rgb_hex(this.g) + d3_rgb_hex(this.b);
  };
  
  function d3_rgb_hex(v) {
    return v < 0x10
        ? "0" + Math.max(0, v).toString(16)
        : Math.min(255, v).toString(16);
  }
  
  function d3_rgb_parse(format, rgb, hsl) {
    var r = 0, // red channel; int in [0, 255]
        g = 0, // green channel; int in [0, 255]
        b = 0, // blue channel; int in [0, 255]
        m1, // CSS color specification match
        m2, // CSS color specification type (e.g., rgb)
        name;
  
    /* Handle hsl, rgb. */
    m1 = /([a-z]+)\((.*)\)/i.exec(format);
    if (m1) {
      m2 = m1[2].split(",");
      switch (m1[1]) {
        case "hsl": {
          return hsl(
            parseFloat(m2[0]), // degrees
            parseFloat(m2[1]) / 100, // percentage
            parseFloat(m2[2]) / 100 // percentage
          );
        }
        case "rgb": {
          return rgb(
            d3_rgb_parseNumber(m2[0]),
            d3_rgb_parseNumber(m2[1]),
            d3_rgb_parseNumber(m2[2])
          );
        }
      }
    }
  
    /* Named colors. */
    if (name = d3_rgb_names.get(format)) return rgb(name.r, name.g, name.b);
  
    /* Hexadecimal colors: #rgb and #rrggbb. */
    if (format != null && format.charAt(0) === "#") {
      if (format.length === 4) {
        r = format.charAt(1); r += r;
        g = format.charAt(2); g += g;
        b = format.charAt(3); b += b;
      } else if (format.length === 7) {
        r = format.substring(1, 3);
        g = format.substring(3, 5);
        b = format.substring(5, 7);
      }
      r = parseInt(r, 16);
      g = parseInt(g, 16);
      b = parseInt(b, 16);
    }
  
    return rgb(r, g, b);
  }
  
  function d3_rgb_hsl(r, g, b) {
    var min = Math.min(r /= 255, g /= 255, b /= 255),
        max = Math.max(r, g, b),
        d = max - min,
        h,
        s,
        l = (max + min) / 2;
    if (d) {
      s = l < .5 ? d / (max + min) : d / (2 - max - min);
      if (r == max) h = (g - b) / d + (g < b ? 6 : 0);
      else if (g == max) h = (b - r) / d + 2;
      else h = (r - g) / d + 4;
      h *= 60;
    } else {
      s = h = 0;
    }
    return d3_hsl(h, s, l);
  }
  
  function d3_rgb_parseNumber(c) { // either integer or percentage
    var f = parseFloat(c);
    return c.charAt(c.length - 1) === "%" ? Math.round(f * 2.55) : f;
  }
  
  var d3_rgb_names = d3.map({
    aliceblue: "#f0f8ff",
    antiquewhite: "#faebd7",
    aqua: "#00ffff",
    aquamarine: "#7fffd4",
    azure: "#f0ffff",
    beige: "#f5f5dc",
    bisque: "#ffe4c4",
    black: "#000000",
    blanchedalmond: "#ffebcd",
    blue: "#0000ff",
    blueviolet: "#8a2be2",
    brown: "#a52a2a",
    burlywood: "#deb887",
    cadetblue: "#5f9ea0",
    chartreuse: "#7fff00",
    chocolate: "#d2691e",
    coral: "#ff7f50",
    cornflowerblue: "#6495ed",
    cornsilk: "#fff8dc",
    crimson: "#dc143c",
    cyan: "#00ffff",
    darkblue: "#00008b",
    darkcyan: "#008b8b",
    darkgoldenrod: "#b8860b",
    darkgray: "#a9a9a9",
    darkgreen: "#006400",
    darkgrey: "#a9a9a9",
    darkkhaki: "#bdb76b",
    darkmagenta: "#8b008b",
    darkolivegreen: "#556b2f",
    darkorange: "#ff8c00",
    darkorchid: "#9932cc",
    darkred: "#8b0000",
    darksalmon: "#e9967a",
    darkseagreen: "#8fbc8f",
    darkslateblue: "#483d8b",
    darkslategray: "#2f4f4f",
    darkslategrey: "#2f4f4f",
    darkturquoise: "#00ced1",
    darkviolet: "#9400d3",
    deeppink: "#ff1493",
    deepskyblue: "#00bfff",
    dimgray: "#696969",
    dimgrey: "#696969",
    dodgerblue: "#1e90ff",
    firebrick: "#b22222",
    floralwhite: "#fffaf0",
    forestgreen: "#228b22",
    fuchsia: "#ff00ff",
    gainsboro: "#dcdcdc",
    ghostwhite: "#f8f8ff",
    gold: "#ffd700",
    goldenrod: "#daa520",
    gray: "#808080",
    green: "#008000",
    greenyellow: "#adff2f",
    grey: "#808080",
    honeydew: "#f0fff0",
    hotpink: "#ff69b4",
    indianred: "#cd5c5c",
    indigo: "#4b0082",
    ivory: "#fffff0",
    khaki: "#f0e68c",
    lavender: "#e6e6fa",
    lavenderblush: "#fff0f5",
    lawngreen: "#7cfc00",
    lemonchiffon: "#fffacd",
    lightblue: "#add8e6",
    lightcoral: "#f08080",
    lightcyan: "#e0ffff",
    lightgoldenrodyellow: "#fafad2",
    lightgray: "#d3d3d3",
    lightgreen: "#90ee90",
    lightgrey: "#d3d3d3",
    lightpink: "#ffb6c1",
    lightsalmon: "#ffa07a",
    lightseagreen: "#20b2aa",
    lightskyblue: "#87cefa",
    lightslategray: "#778899",
    lightslategrey: "#778899",
    lightsteelblue: "#b0c4de",
    lightyellow: "#ffffe0",
    lime: "#00ff00",
    limegreen: "#32cd32",
    linen: "#faf0e6",
    magenta: "#ff00ff",
    maroon: "#800000",
    mediumaquamarine: "#66cdaa",
    mediumblue: "#0000cd",
    mediumorchid: "#ba55d3",
    mediumpurple: "#9370db",
    mediumseagreen: "#3cb371",
    mediumslateblue: "#7b68ee",
    mediumspringgreen: "#00fa9a",
    mediumturquoise: "#48d1cc",
    mediumvioletred: "#c71585",
    midnightblue: "#191970",
    mintcream: "#f5fffa",
    mistyrose: "#ffe4e1",
    moccasin: "#ffe4b5",
    navajowhite: "#ffdead",
    navy: "#000080",
    oldlace: "#fdf5e6",
    olive: "#808000",
    olivedrab: "#6b8e23",
    orange: "#ffa500",
    orangered: "#ff4500",
    orchid: "#da70d6",
    palegoldenrod: "#eee8aa",
    palegreen: "#98fb98",
    paleturquoise: "#afeeee",
    palevioletred: "#db7093",
    papayawhip: "#ffefd5",
    peachpuff: "#ffdab9",
    peru: "#cd853f",
    pink: "#ffc0cb",
    plum: "#dda0dd",
    powderblue: "#b0e0e6",
    purple: "#800080",
    red: "#ff0000",
    rosybrown: "#bc8f8f",
    royalblue: "#4169e1",
    saddlebrown: "#8b4513",
    salmon: "#fa8072",
    sandybrown: "#f4a460",
    seagreen: "#2e8b57",
    seashell: "#fff5ee",
    sienna: "#a0522d",
    silver: "#c0c0c0",
    skyblue: "#87ceeb",
    slateblue: "#6a5acd",
    slategray: "#708090",
    slategrey: "#708090",
    snow: "#fffafa",
    springgreen: "#00ff7f",
    steelblue: "#4682b4",
    tan: "#d2b48c",
    teal: "#008080",
    thistle: "#d8bfd8",
    tomato: "#ff6347",
    turquoise: "#40e0d0",
    violet: "#ee82ee",
    wheat: "#f5deb3",
    white: "#ffffff",
    whitesmoke: "#f5f5f5",
    yellow: "#ffff00",
    yellowgreen: "#9acd32"
  });
  
  d3_rgb_names.forEach(function(key, value) {
    d3_rgb_names.set(key, d3_rgb_parse(value, d3_rgb, d3_hsl_rgb));
  });
  d3.hsl = function(h, s, l) {
    return arguments.length === 1
        ? (h instanceof d3_Hsl ? d3_hsl(h.h, h.s, h.l)
        : d3_rgb_parse("" + h, d3_rgb_hsl, d3_hsl))
        : d3_hsl(+h, +s, +l);
  };
  
  function d3_hsl(h, s, l) {
    return new d3_Hsl(h, s, l);
  }
  
  function d3_Hsl(h, s, l) {
    this.h = h;
    this.s = s;
    this.l = l;
  }
  
  d3_Hsl.prototype.brighter = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_hsl(this.h, this.s, this.l / k);
  };
  
  d3_Hsl.prototype.darker = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_hsl(this.h, this.s, k * this.l);
  };
  
  d3_Hsl.prototype.rgb = function() {
    return d3_hsl_rgb(this.h, this.s, this.l);
  };
  
  d3_Hsl.prototype.toString = function() {
    return this.rgb().toString();
  };
  
  function d3_hsl_rgb(h, s, l) {
    var m1,
        m2;
  
    /* Some simple corrections for h, s and l. */
    h = h % 360; if (h < 0) h += 360;
    s = s < 0 ? 0 : s > 1 ? 1 : s;
    l = l < 0 ? 0 : l > 1 ? 1 : l;
  
    /* From FvD 13.37, CSS Color Module Level 3 */
    m2 = l <= .5 ? l * (1 + s) : l + s - l * s;
    m1 = 2 * l - m2;
  
    function v(h) {
      if (h > 360) h -= 360;
      else if (h < 0) h += 360;
      if (h < 60) return m1 + (m2 - m1) * h / 60;
      if (h < 180) return m2;
      if (h < 240) return m1 + (m2 - m1) * (240 - h) / 60;
      return m1;
    }
  
    function vv(h) {
      return Math.round(v(h) * 255);
    }
  
    return d3_rgb(vv(h + 120), vv(h), vv(h - 120));
  }
  function d3_selection(groups) {
    d3_arraySubclass(groups, d3_selectionPrototype);
    return groups;
  }
  
  var d3_select = function(s, n) { return n.querySelector(s); },
      d3_selectAll = function(s, n) { return n.querySelectorAll(s); },
      d3_selectRoot = document.documentElement,
      d3_selectMatcher = d3_selectRoot.matchesSelector || d3_selectRoot.webkitMatchesSelector || d3_selectRoot.mozMatchesSelector || d3_selectRoot.msMatchesSelector || d3_selectRoot.oMatchesSelector,
      d3_selectMatches = function(n, s) { return d3_selectMatcher.call(n, s); };
  
  // Prefer Sizzle, if available.
  if (typeof Sizzle === "function") {
    d3_select = function(s, n) { return Sizzle(s, n)[0]; };
    d3_selectAll = function(s, n) { return Sizzle.uniqueSort(Sizzle(s, n)); };
    d3_selectMatches = Sizzle.matchesSelector;
  }
  
  var d3_selectionPrototype = [];
  
  d3.selection = function() {
    return d3_selectionRoot;
  };
  
  d3.selection.prototype = d3_selectionPrototype;
  d3_selectionPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        group,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selector(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      subgroup.parentNode = (group = this[j]).parentNode;
      for (var i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroup.push(subnode = selector.call(node, node.__data__, i));
          if (subnode && "__data__" in node) subnode.__data__ = node.__data__;
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  
  function d3_selection_selector(selector) {
    return function() {
      return d3_select(selector, this);
    };
  }
  d3_selectionPrototype.selectAll = function(selector) {
    var subgroups = [],
        subgroup,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selectorAll(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroups.push(subgroup = d3_array(selector.call(node, node.__data__, i)));
          subgroup.parentNode = node;
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  
  function d3_selection_selectorAll(selector) {
    return function() {
      return d3_selectAll(selector, this);
    };
  }
  d3_selectionPrototype.attr = function(name, value) {
    name = d3.ns.qualify(name);
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) {
      var node = this.node();
      return name.local
          ? node.getAttributeNS(name.space, name.local)
          : node.getAttribute(name);
    }
  
    function attrNull() {
      this.removeAttribute(name);
    }
  
    function attrNullNS() {
      this.removeAttributeNS(name.space, name.local);
    }
  
    function attrConstant() {
      this.setAttribute(name, value);
    }
  
    function attrConstantNS() {
      this.setAttributeNS(name.space, name.local, value);
    }
  
    function attrFunction() {
      var x = value.apply(this, arguments);
      if (x == null) this.removeAttribute(name);
      else this.setAttribute(name, x);
    }
  
    function attrFunctionNS() {
      var x = value.apply(this, arguments);
      if (x == null) this.removeAttributeNS(name.space, name.local);
      else this.setAttributeNS(name.space, name.local, x);
    }
  
    return this.each(value == null
        ? (name.local ? attrNullNS : attrNull) : (typeof value === "function"
        ? (name.local ? attrFunctionNS : attrFunction)
        : (name.local ? attrConstantNS : attrConstant)));
  };
  d3_selectionPrototype.classed = function(name, value) {
    var names = name.split(d3_selection_classedWhitespace),
        n = names.length,
        i = -1;
    if (arguments.length > 1) {
      while (++i < n) d3_selection_classed.call(this, names[i], value);
      return this;
    } else {
      while (++i < n) if (!d3_selection_classed.call(this, names[i])) return false;
      return true;
    }
  };
  
  var d3_selection_classedWhitespace = /\s+/g;
  
  function d3_selection_classed(name, value) {
    var re = new RegExp("(^|\\s+)" + d3.requote(name) + "(\\s+|$)", "g");
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) {
      var node = this.node();
      if (c = node.classList) return c.contains(name);
      var c = node.className;
      re.lastIndex = 0;
      return re.test(c.baseVal != null ? c.baseVal : c);
    }
  
    function classedAdd() {
      if (c = this.classList) return c.add(name);
      var c = this.className,
          cb = c.baseVal != null,
          cv = cb ? c.baseVal : c;
      re.lastIndex = 0;
      if (!re.test(cv)) {
        cv = d3_collapse(cv + " " + name);
        if (cb) c.baseVal = cv;
        else this.className = cv;
      }
    }
  
    function classedRemove() {
      if (c = this.classList) return c.remove(name);
      var c = this.className,
          cb = c.baseVal != null,
          cv = cb ? c.baseVal : c;
      cv = d3_collapse(cv.replace(re, " "));
      if (cb) c.baseVal = cv;
      else this.className = cv;
    }
  
    function classedFunction() {
      (value.apply(this, arguments)
          ? classedAdd
          : classedRemove).call(this);
    }
  
    return this.each(typeof value === "function"
        ? classedFunction : value
        ? classedAdd
        : classedRemove);
  }
  d3_selectionPrototype.style = function(name, value, priority) {
    if (arguments.length < 3) priority = "";
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) return window
        .getComputedStyle(this.node(), null)
        .getPropertyValue(name);
  
    function styleNull() {
      this.style.removeProperty(name);
    }
  
    function styleConstant() {
      this.style.setProperty(name, value, priority);
    }
  
    function styleFunction() {
      var x = value.apply(this, arguments);
      if (x == null) this.style.removeProperty(name);
      else this.style.setProperty(name, x, priority);
    }
  
    return this.each(value == null
        ? styleNull : (typeof value === "function"
        ? styleFunction : styleConstant));
  };
  d3_selectionPrototype.property = function(name, value) {
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) return this.node()[name];
  
    function propertyNull() {
      delete this[name];
    }
  
    function propertyConstant() {
      this[name] = value;
    }
  
    function propertyFunction() {
      var x = value.apply(this, arguments);
      if (x == null) delete this[name];
      else this[name] = x;
    }
  
    return this.each(value == null
        ? propertyNull : (typeof value === "function"
        ? propertyFunction : propertyConstant));
  };
  d3_selectionPrototype.text = function(value) {
    return arguments.length < 1
        ? this.node().textContent : this.each(typeof value === "function"
        ? function() { var v = value.apply(this, arguments); this.textContent = v == null ? "" : v; } : value == null
        ? function() { this.textContent = ""; }
        : function() { this.textContent = value; });
  };
  d3_selectionPrototype.html = function(value) {
    return arguments.length < 1
        ? this.node().innerHTML : this.each(typeof value === "function"
        ? function() { var v = value.apply(this, arguments); this.innerHTML = v == null ? "" : v; } : value == null
        ? function() { this.innerHTML = ""; }
        : function() { this.innerHTML = value; });
  };
  // TODO append(node)?
  // TODO append(function)?
  d3_selectionPrototype.append = function(name) {
    name = d3.ns.qualify(name);
  
    function append() {
      return this.appendChild(document.createElementNS(this.namespaceURI, name));
    }
  
    function appendNS() {
      return this.appendChild(document.createElementNS(name.space, name.local));
    }
  
    return this.select(name.local ? appendNS : append);
  };
  // TODO insert(node, function)?
  // TODO insert(function, string)?
  // TODO insert(function, function)?
  d3_selectionPrototype.insert = function(name, before) {
    name = d3.ns.qualify(name);
  
    function insert() {
      return this.insertBefore(
          document.createElementNS(this.namespaceURI, name),
          d3_select(before, this));
    }
  
    function insertNS() {
      return this.insertBefore(
          document.createElementNS(name.space, name.local),
          d3_select(before, this));
    }
  
    return this.select(name.local ? insertNS : insert);
  };
  // TODO remove(selector)?
  // TODO remove(node)?
  // TODO remove(function)?
  d3_selectionPrototype.remove = function() {
    return this.each(function() {
      var parent = this.parentNode;
      if (parent) parent.removeChild(this);
    });
  };
  d3_selectionPrototype.data = function(value, key) {
    var i = -1,
        n = this.length,
        group,
        node;
  
    // If no value is specified, return the first value.
    if (!arguments.length) {
      value = new Array(n = (group = this[0]).length);
      while (++i < n) {
        if (node = group[i]) {
          value[i] = node.__data__;
        }
      }
      return value;
    }
  
    function bind(group, groupData) {
      var i,
          n = group.length,
          m = groupData.length,
          n0 = Math.min(n, m),
          n1 = Math.max(n, m),
          updateNodes = [],
          enterNodes = [],
          exitNodes = [],
          node,
          nodeData;
  
      if (key) {
        var nodeByKeyValue = new d3_Map,
            keyValues = [],
            keyValue,
            j = groupData.length;
  
        for (i = -1; ++i < n;) {
          keyValue = key.call(node = group[i], node.__data__, i);
          if (nodeByKeyValue.has(keyValue)) {
            exitNodes[j++] = node; // duplicate key
          } else {
            nodeByKeyValue.set(keyValue, node);
          }
          keyValues.push(keyValue);
        }
  
        for (i = -1; ++i < m;) {
          keyValue = key.call(groupData, nodeData = groupData[i], i)
          if (nodeByKeyValue.has(keyValue)) {
            updateNodes[i] = node = nodeByKeyValue.get(keyValue);
            node.__data__ = nodeData;
            enterNodes[i] = exitNodes[i] = null;
          } else {
            enterNodes[i] = d3_selection_dataNode(nodeData);
            updateNodes[i] = exitNodes[i] = null;
          }
          nodeByKeyValue.remove(keyValue);
        }
  
        for (i = -1; ++i < n;) {
          if (nodeByKeyValue.has(keyValues[i])) {
            exitNodes[i] = group[i];
          }
        }
      } else {
        for (i = -1; ++i < n0;) {
          node = group[i];
          nodeData = groupData[i];
          if (node) {
            node.__data__ = nodeData;
            updateNodes[i] = node;
            enterNodes[i] = exitNodes[i] = null;
          } else {
            enterNodes[i] = d3_selection_dataNode(nodeData);
            updateNodes[i] = exitNodes[i] = null;
          }
        }
        for (; i < m; ++i) {
          enterNodes[i] = d3_selection_dataNode(groupData[i]);
          updateNodes[i] = exitNodes[i] = null;
        }
        for (; i < n1; ++i) {
          exitNodes[i] = group[i];
          enterNodes[i] = updateNodes[i] = null;
        }
      }
  
      enterNodes.update
          = updateNodes;
  
      enterNodes.parentNode
          = updateNodes.parentNode
          = exitNodes.parentNode
          = group.parentNode;
  
      enter.push(enterNodes);
      update.push(updateNodes);
      exit.push(exitNodes);
    }
  
    var enter = d3_selection_enter([]),
        update = d3_selection([]),
        exit = d3_selection([]);
  
    if (typeof value === "function") {
      while (++i < n) {
        bind(group = this[i], value.call(group, group.parentNode.__data__, i));
      }
    } else {
      while (++i < n) {
        bind(group = this[i], value);
      }
    }
  
    update.enter = function() { return enter; };
    update.exit = function() { return exit; };
    return update;
  };
  
  function d3_selection_dataNode(data) {
    return {__data__: data};
  }
  d3_selectionPrototype.datum =
  d3_selectionPrototype.map = function(value) {
    return arguments.length < 1
        ? this.property("__data__")
        : this.property("__data__", value);
  };
  d3_selectionPrototype.filter = function(filter) {
    var subgroups = [],
        subgroup,
        group,
        node;
  
    if (typeof filter !== "function") filter = d3_selection_filter(filter);
  
    for (var j = 0, m = this.length; j < m; j++) {
      subgroups.push(subgroup = []);
      subgroup.parentNode = (group = this[j]).parentNode;
      for (var i = 0, n = group.length; i < n; i++) {
        if ((node = group[i]) && filter.call(node, node.__data__, i)) {
          subgroup.push(node);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  
  function d3_selection_filter(selector) {
    return function() {
      return d3_selectMatches(this, selector);
    };
  }
  d3_selectionPrototype.order = function() {
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
        if (node = group[i]) {
          if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
          next = node;
        }
      }
    }
    return this;
  };
  d3_selectionPrototype.sort = function(comparator) {
    comparator = d3_selection_sortComparator.apply(this, arguments);
    for (var j = -1, m = this.length; ++j < m;) this[j].sort(comparator);
    return this.order();
  };
  
  function d3_selection_sortComparator(comparator) {
    if (!arguments.length) comparator = d3.ascending;
    return function(a, b) {
      return comparator(a && a.__data__, b && b.__data__);
    };
  }
  // type can be namespaced, e.g., "click.foo"
  // listener can be null for removal
  d3_selectionPrototype.on = function(type, listener, capture) {
    if (arguments.length < 3) capture = false;
  
    // parse the type specifier
    var name = "__on" + type, i = type.indexOf(".");
    if (i > 0) type = type.substring(0, i);
  
    // if called with only one argument, return the current listener
    if (arguments.length < 2) return (i = this.node()[name]) && i._;
  
    // remove the old event listener, and add the new event listener
    return this.each(function(d, i) {
      var node = this,
          o = node[name];
  
      // remove the old listener, if any (using the previously-set capture)
      if (o) {
        node.removeEventListener(type, o, o.$);
        delete node[name];
      }
  
      // add the new listener, if any (remembering the capture flag)
      if (listener) {
        node.addEventListener(type, node[name] = l, l.$ = capture);
        l._ = listener; // stash the unwrapped listener for get
      }
  
      // wrapped event listener that preserves i
      function l(e) {
        var o = d3.event; // Events can be reentrant (e.g., focus).
        d3.event = e;
        try {
          listener.call(node, node.__data__, i);
        } finally {
          d3.event = o;
        }
      }
    });
  };
  d3_selectionPrototype.each = function(callback) {
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        var node = group[i];
        if (node) callback.call(node, node.__data__, i, j);
      }
    }
    return this;
  };
  //
  // Note: assigning to the arguments array simultaneously changes the value of
  // the corresponding argument!
  //
  // TODO The `this` argument probably shouldn't be the first argument to the
  // callback, anyway, since it's redundant. However, that will require a major
  // version bump due to backwards compatibility, so I'm not changing it right
  // away.
  //
  d3_selectionPrototype.call = function(callback) {
    callback.apply(this, (arguments[0] = this, arguments));
    return this;
  };
  d3_selectionPrototype.empty = function() {
    return !this.node();
  };
  d3_selectionPrototype.node = function(callback) {
    for (var j = 0, m = this.length; j < m; j++) {
      for (var group = this[j], i = 0, n = group.length; i < n; i++) {
        var node = group[i];
        if (node) return node;
      }
    }
    return null;
  };
  d3_selectionPrototype.transition = function() {
    var subgroups = [],
        subgroup,
        node;
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        subgroup.push((node = group[i]) ? {node: node, delay: d3_transitionDelay, duration: d3_transitionDuration} : null);
      }
    }
  
    return d3_transition(subgroups, d3_transitionId || ++d3_transitionNextId, Date.now());
  };
  var d3_selectionRoot = d3_selection([[document]]);
  
  d3_selectionRoot[0].parentNode = d3_selectRoot;
  
  // TODO fast singleton implementation!
  // TODO select(function)
  d3.select = function(selector) {
    return typeof selector === "string"
        ? d3_selectionRoot.select(selector)
        : d3_selection([[selector]]); // assume node
  };
  
  // TODO selectAll(function)
  d3.selectAll = function(selector) {
    return typeof selector === "string"
        ? d3_selectionRoot.selectAll(selector)
        : d3_selection([d3_array(selector)]); // assume node[]
  };
  function d3_selection_enter(selection) {
    d3_arraySubclass(selection, d3_selection_enterPrototype);
    return selection;
  }
  
  var d3_selection_enterPrototype = [];
  
  d3.selection.enter = d3_selection_enter;
  d3.selection.enter.prototype = d3_selection_enterPrototype;
  
  d3_selection_enterPrototype.append = d3_selectionPrototype.append;
  d3_selection_enterPrototype.insert = d3_selectionPrototype.insert;
  d3_selection_enterPrototype.empty = d3_selectionPrototype.empty;
  d3_selection_enterPrototype.node = d3_selectionPrototype.node;
  d3_selection_enterPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        upgroup,
        group,
        node;
  
    for (var j = -1, m = this.length; ++j < m;) {
      upgroup = (group = this[j]).update;
      subgroups.push(subgroup = []);
      subgroup.parentNode = group.parentNode;
      for (var i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroup.push(upgroup[i] = subnode = selector.call(group.parentNode, node.__data__, i));
          subnode.__data__ = node.__data__;
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  function d3_transition(groups, id, time) {
    d3_arraySubclass(groups, d3_transitionPrototype);
  
    var tweens = new d3_Map,
        event = d3.dispatch("start", "end"),
        ease = d3_transitionEase;
  
    groups.id = id;
  
    groups.time = time;
  
    groups.tween = function(name, tween) {
      if (arguments.length < 2) return tweens.get(name);
      if (tween == null) tweens.remove(name);
      else tweens.set(name, tween);
      return groups;
    };
  
    groups.ease = function(value) {
      if (!arguments.length) return ease;
      ease = typeof value === "function" ? value : d3.ease.apply(d3, arguments);
      return groups;
    };
  
    groups.each = function(type, listener) {
      if (arguments.length < 2) return d3_transition_each.call(groups, type);
      event.on(type, listener);
      return groups;
    };
  
    d3.timer(function(elapsed) {
      groups.each(function(d, i, j) {
        var tweened = [],
            node = this,
            delay = groups[j][i].delay,
            duration = groups[j][i].duration,
            lock = node.__transition__ || (node.__transition__ = {active: 0, count: 0});
  
        ++lock.count;
  
        delay <= elapsed ? start(elapsed) : d3.timer(start, delay, time);
  
        function start(elapsed) {
          if (lock.active > id) return stop();
          lock.active = id;
  
          tweens.forEach(function(key, value) {
            if (tween = value.call(node, d, i)) {
              tweened.push(tween);
            }
          });
  
          event.start.call(node, d, i);
          if (!tick(elapsed)) d3.timer(tick, 0, time);
          return 1;
        }
  
        function tick(elapsed) {
          if (lock.active !== id) return stop();
  
          var t = (elapsed - delay) / duration,
              e = ease(t),
              n = tweened.length;
  
          while (n > 0) {
            tweened[--n].call(node, e);
          }
  
          if (t >= 1) {
            stop();
            d3_transitionId = id;
            event.end.call(node, d, i);
            d3_transitionId = 0;
            return 1;
          }
        }
  
        function stop() {
          if (!--lock.count) delete node.__transition__;
          return 1;
        }
      });
      return 1;
    }, 0, time);
  
    return groups;
  }
  
  var d3_transitionRemove = {};
  
  function d3_transitionNull(d, i, a) {
    return a != "" && d3_transitionRemove;
  }
  
  function d3_transitionTween(name, b) {
    var interpolate = d3_interpolateByName(name);
  
    function transitionFunction(d, i, a) {
      var v = b.call(this, d, i);
      return v == null
          ? a != "" && d3_transitionRemove
          : a != v && interpolate(a, v);
    }
  
    function transitionString(d, i, a) {
      return a != b && interpolate(a, b);
    }
  
    return typeof b === "function" ? transitionFunction
        : b == null ? d3_transitionNull
        : (b += "", transitionString);
  }
  
  var d3_transitionPrototype = [],
      d3_transitionNextId = 0,
      d3_transitionId = 0,
      d3_transitionDefaultDelay = 0,
      d3_transitionDefaultDuration = 250,
      d3_transitionDefaultEase = d3.ease("cubic-in-out"),
      d3_transitionDelay = d3_transitionDefaultDelay,
      d3_transitionDuration = d3_transitionDefaultDuration,
      d3_transitionEase = d3_transitionDefaultEase;
  
  d3_transitionPrototype.call = d3_selectionPrototype.call;
  
  d3.transition = function(selection) {
    return arguments.length
        ? (d3_transitionId ? selection.transition() : selection)
        : d3_selectionRoot.transition();
  };
  
  d3.transition.prototype = d3_transitionPrototype;
  d3_transitionPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selector(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if ((node = group[i]) && (subnode = selector.call(node.node, node.node.__data__, i))) {
          if ("__data__" in node.node) subnode.__data__ = node.node.__data__;
          subgroup.push({node: subnode, delay: node.delay, duration: node.duration});
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_transition(subgroups, this.id, this.time).ease(this.ease());
  };
  d3_transitionPrototype.selectAll = function(selector) {
    var subgroups = [],
        subgroup,
        subnodes,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selectorAll(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subnodes = selector.call(node.node, node.node.__data__, i);
          subgroups.push(subgroup = []);
          for (var k = -1, o = subnodes.length; ++k < o;) {
            subgroup.push({node: subnodes[k], delay: node.delay, duration: node.duration});
          }
        }
      }
    }
  
    return d3_transition(subgroups, this.id, this.time).ease(this.ease());
  };
  d3_transitionPrototype.attr = function(name, value) {
    return this.attrTween(name, d3_transitionTween(name, value));
  };
  
  d3_transitionPrototype.attrTween = function(nameNS, tween) {
    var name = d3.ns.qualify(nameNS);
  
    function attrTween(d, i) {
      var f = tween.call(this, d, i, this.getAttribute(name));
      return f === d3_transitionRemove
          ? (this.removeAttribute(name), null)
          : f && function(t) { this.setAttribute(name, f(t)); };
    }
  
    function attrTweenNS(d, i) {
      var f = tween.call(this, d, i, this.getAttributeNS(name.space, name.local));
      return f === d3_transitionRemove
          ? (this.removeAttributeNS(name.space, name.local), null)
          : f && function(t) { this.setAttributeNS(name.space, name.local, f(t)); };
    }
  
    return this.tween("attr." + nameNS, name.local ? attrTweenNS : attrTween);
  };
  d3_transitionPrototype.style = function(name, value, priority) {
    if (arguments.length < 3) priority = "";
    return this.styleTween(name, d3_transitionTween(name, value), priority);
  };
  
  d3_transitionPrototype.styleTween = function(name, tween, priority) {
    if (arguments.length < 3) priority = "";
    return this.tween("style." + name, function(d, i) {
      var f = tween.call(this, d, i, window.getComputedStyle(this, null).getPropertyValue(name));
      return f === d3_transitionRemove
          ? (this.style.removeProperty(name), null)
          : f && function(t) { this.style.setProperty(name, f(t), priority); };
    });
  };
  d3_transitionPrototype.text = function(value) {
    return this.tween("text", function(d, i) {
      this.textContent = typeof value === "function"
          ? value.call(this, d, i)
          : value;
    });
  };
  d3_transitionPrototype.remove = function() {
    return this.each("end.transition", function() {
      var p;
      if (!this.__transition__ && (p = this.parentNode)) p.removeChild(this);
    });
  };
  d3_transitionPrototype.delay = function(value) {
    var groups = this;
    return groups.each(typeof value === "function"
        ? function(d, i, j) { groups[j][i].delay = value.apply(this, arguments) | 0; }
        : (value = value | 0, function(d, i, j) { groups[j][i].delay = value; }));
  };
  d3_transitionPrototype.duration = function(value) {
    var groups = this;
    return groups.each(typeof value === "function"
        ? function(d, i, j) { groups[j][i].duration = Math.max(1, value.apply(this, arguments) | 0); }
        : (value = Math.max(1, value | 0), function(d, i, j) { groups[j][i].duration = value; }));
  };
  function d3_transition_each(callback) {
    var id = d3_transitionId,
        ease = d3_transitionEase,
        delay = d3_transitionDelay,
        duration = d3_transitionDuration;
  
    d3_transitionId = this.id;
    d3_transitionEase = this.ease();
    for (var j = 0, m = this.length; j < m; j++) {
      for (var group = this[j], i = 0, n = group.length; i < n; i++) {
        var node = group[i];
        if (node) {
          d3_transitionDelay = this[j][i].delay;
          d3_transitionDuration = this[j][i].duration;
          callback.call(node = node.node, node.__data__, i, j);
        }
      }
    }
  
    d3_transitionId = id;
    d3_transitionEase = ease;
    d3_transitionDelay = delay;
    d3_transitionDuration = duration;
    return this;
  }
  d3_transitionPrototype.transition = function() {
    return this.select(d3_this);
  };
  var d3_timer_queue = null,
      d3_timer_interval, // is an interval (or frame) active?
      d3_timer_timeout; // is a timeout active?
  
  // The timer will continue to fire until callback returns true.
  d3.timer = function(callback, delay, then) {
    var found = false,
        t0,
        t1 = d3_timer_queue;
  
    if (arguments.length < 3) {
      if (arguments.length < 2) delay = 0;
      else if (!isFinite(delay)) return;
      then = Date.now();
    }
  
    // See if the callback's already in the queue.
    while (t1) {
      if (t1.callback === callback) {
        t1.then = then;
        t1.delay = delay;
        found = true;
        break;
      }
      t0 = t1;
      t1 = t1.next;
    }
  
    // Otherwise, add the callback to the queue.
    if (!found) d3_timer_queue = {
      callback: callback,
      then: then,
      delay: delay,
      next: d3_timer_queue
    };
  
    // Start animatin'!
    if (!d3_timer_interval) {
      d3_timer_timeout = clearTimeout(d3_timer_timeout);
      d3_timer_interval = 1;
      d3_timer_frame(d3_timer_step);
    }
  }
  
  function d3_timer_step() {
    var elapsed,
        now = Date.now(),
        t1 = d3_timer_queue;
  
    while (t1) {
      elapsed = now - t1.then;
      if (elapsed >= t1.delay) t1.flush = t1.callback(elapsed);
      t1 = t1.next;
    }
  
    var delay = d3_timer_flush() - now;
    if (delay > 24) {
      if (isFinite(delay)) {
        clearTimeout(d3_timer_timeout);
        d3_timer_timeout = setTimeout(d3_timer_step, delay);
      }
      d3_timer_interval = 0;
    } else {
      d3_timer_interval = 1;
      d3_timer_frame(d3_timer_step);
    }
  }
  
  d3.timer.flush = function() {
    var elapsed,
        now = Date.now(),
        t1 = d3_timer_queue;
  
    while (t1) {
      elapsed = now - t1.then;
      if (!t1.delay) t1.flush = t1.callback(elapsed);
      t1 = t1.next;
    }
  
    d3_timer_flush();
  };
  
  // Flush after callbacks, to avoid concurrent queue modification.
  function d3_timer_flush() {
    var t0 = null,
        t1 = d3_timer_queue,
        then = Infinity;
    while (t1) {
      if (t1.flush) {
        t1 = t0 ? t0.next = t1.next : d3_timer_queue = t1.next;
      } else {
        then = Math.min(then, t1.then + t1.delay);
        t1 = (t0 = t1).next;
      }
    }
    return then;
  }
  
  var d3_timer_frame = window.requestAnimationFrame
      || window.webkitRequestAnimationFrame
      || window.mozRequestAnimationFrame
      || window.oRequestAnimationFrame
      || window.msRequestAnimationFrame
      || function(callback) { setTimeout(callback, 17); };
  d3.transform = function(string) {
    var g = document.createElementNS(d3.ns.prefix.svg, "g"),
        identity = {a: 1, b: 0, c: 0, d: 1, e: 0, f: 0};
    return (d3.transform = function(string) {
      g.setAttribute("transform", string);
      var t = g.transform.baseVal.consolidate();
      return new d3_transform(t ? t.matrix : identity);
    })(string);
  };
  
  // Compute x-scale and normalize the first row.
  // Compute shear and make second row orthogonal to first.
  // Compute y-scale and normalize the second row.
  // Finally, compute the rotation.
  function d3_transform(m) {
    var r0 = [m.a, m.b],
        r1 = [m.c, m.d],
        kx = d3_transformNormalize(r0),
        kz = d3_transformDot(r0, r1),
        ky = d3_transformNormalize(d3_transformCombine(r1, r0, -kz)) || 0;
    if (r0[0] * r1[1] < r1[0] * r0[1]) {
      r0[0] *= -1;
      r0[1] *= -1;
      kx *= -1;
      kz *= -1;
    }
    this.rotate = (kx ? Math.atan2(r0[1], r0[0]) : Math.atan2(-r1[0], r1[1])) * d3_transformDegrees;
    this.translate = [m.e, m.f];
    this.scale = [kx, ky];
    this.skew = ky ? Math.atan2(kz, ky) * d3_transformDegrees : 0;
  };
  
  d3_transform.prototype.toString = function() {
    return "translate(" + this.translate
        + ")rotate(" + this.rotate
        + ")skewX(" + this.skew
        + ")scale(" + this.scale
        + ")";
  };
  
  function d3_transformDot(a, b) {
    return a[0] * b[0] + a[1] * b[1];
  }
  
  function d3_transformNormalize(a) {
    var k = Math.sqrt(d3_transformDot(a, a));
    if (k) {
      a[0] /= k;
      a[1] /= k;
    }
    return k;
  }
  
  function d3_transformCombine(a, b, k) {
    a[0] += k * b[0];
    a[1] += k * b[1];
    return a;
  }
  
  var d3_transformDegrees = 180 / Math.PI;
  d3.mouse = function(container) {
    return d3_mousePoint(container, d3_eventSource());
  };
  
  // https://bugs.webkit.org/show_bug.cgi?id=44083
  var d3_mouse_bug44083 = /WebKit/.test(navigator.userAgent) ? -1 : 0;
  
  function d3_mousePoint(container, e) {
    var svg = container.ownerSVGElement || container;
    if (svg.createSVGPoint) {
      var point = svg.createSVGPoint();
      if ((d3_mouse_bug44083 < 0) && (window.scrollX || window.scrollY)) {
        svg = d3.select(document.body)
          .append("svg")
            .style("position", "absolute")
            .style("top", 0)
            .style("left", 0);
        var ctm = svg[0][0].getScreenCTM();
        d3_mouse_bug44083 = !(ctm.f || ctm.e);
        svg.remove();
      }
      if (d3_mouse_bug44083) {
        point.x = e.pageX;
        point.y = e.pageY;
      } else {
        point.x = e.clientX;
        point.y = e.clientY;
      }
      point = point.matrixTransform(container.getScreenCTM().inverse());
      return [point.x, point.y];
    }
    var rect = container.getBoundingClientRect();
    return [e.clientX - rect.left - container.clientLeft, e.clientY - rect.top - container.clientTop];
  };
  d3.touches = function(container, touches) {
    if (arguments.length < 2) touches = d3_eventSource().touches;
    return touches ? d3_array(touches).map(function(touch) {
      var point = d3_mousePoint(container, touch);
      point.identifier = touch.identifier;
      return point;
    }) : [];
  };
  function d3_noop() {}
  d3.scale = {};
  
  function d3_scaleExtent(domain) {
    var start = domain[0], stop = domain[domain.length - 1];
    return start < stop ? [start, stop] : [stop, start];
  }
  
  function d3_scaleRange(scale) {
    return scale.rangeExtent ? scale.rangeExtent() : d3_scaleExtent(scale.range());
  }
  function d3_scale_nice(domain, nice) {
    var i0 = 0,
        i1 = domain.length - 1,
        x0 = domain[i0],
        x1 = domain[i1],
        dx;
  
    if (x1 < x0) {
      dx = i0; i0 = i1; i1 = dx;
      dx = x0; x0 = x1; x1 = dx;
    }
  
    if (dx = x1 - x0) {
      nice = nice(dx);
      domain[i0] = nice.floor(x0);
      domain[i1] = nice.ceil(x1);
    }
  
    return domain;
  }
  
  function d3_scale_niceDefault() {
    return Math;
  }
  d3.scale.linear = function() {
    return d3_scale_linear([0, 1], [0, 1], d3.interpolate, false);
  };
  
  function d3_scale_linear(domain, range, interpolate, clamp) {
    var output,
        input;
  
    function rescale() {
      var linear = Math.min(domain.length, range.length) > 2 ? d3_scale_polylinear : d3_scale_bilinear,
          uninterpolate = clamp ? d3_uninterpolateClamp : d3_uninterpolateNumber;
      output = linear(domain, range, uninterpolate, interpolate);
      input = linear(range, domain, uninterpolate, d3.interpolate);
      return scale;
    }
  
    function scale(x) {
      return output(x);
    }
  
    // Note: requires range is coercible to number!
    scale.invert = function(y) {
      return input(y);
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = x.map(Number);
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.rangeRound = function(x) {
      return scale.range(x).interpolate(d3.interpolateRound);
    };
  
    scale.clamp = function(x) {
      if (!arguments.length) return clamp;
      clamp = x;
      return rescale();
    };
  
    scale.interpolate = function(x) {
      if (!arguments.length) return interpolate;
      interpolate = x;
      return rescale();
    };
  
    scale.ticks = function(m) {
      return d3_scale_linearTicks(domain, m);
    };
  
    scale.tickFormat = function(m) {
      return d3_scale_linearTickFormat(domain, m);
    };
  
    scale.nice = function() {
      d3_scale_nice(domain, d3_scale_linearNice);
      return rescale();
    };
  
    scale.copy = function() {
      return d3_scale_linear(domain, range, interpolate, clamp);
    };
  
    return rescale();
  }
  
  function d3_scale_linearRebind(scale, linear) {
    return d3.rebind(scale, linear, "range", "rangeRound", "interpolate", "clamp");
  }
  
  function d3_scale_linearNice(dx) {
    dx = Math.pow(10, Math.round(Math.log(dx) / Math.LN10) - 1);
    return {
      floor: function(x) { return Math.floor(x / dx) * dx; },
      ceil: function(x) { return Math.ceil(x / dx) * dx; }
    };
  }
  
  function d3_scale_linearTickRange(domain, m) {
    var extent = d3_scaleExtent(domain),
        span = extent[1] - extent[0],
        step = Math.pow(10, Math.floor(Math.log(span / m) / Math.LN10)),
        err = m / span * step;
  
    // Filter ticks to get closer to the desired count.
    if (err <= .15) step *= 10;
    else if (err <= .35) step *= 5;
    else if (err <= .75) step *= 2;
  
    // Round start and stop values to step interval.
    extent[0] = Math.ceil(extent[0] / step) * step;
    extent[1] = Math.floor(extent[1] / step) * step + step * .5; // inclusive
    extent[2] = step;
    return extent;
  }
  
  function d3_scale_linearTicks(domain, m) {
    return d3.range.apply(d3, d3_scale_linearTickRange(domain, m));
  }
  
  function d3_scale_linearTickFormat(domain, m) {
    return d3.format(",." + Math.max(0, -Math.floor(Math.log(d3_scale_linearTickRange(domain, m)[2]) / Math.LN10 + .01)) + "f");
  }
  function d3_scale_bilinear(domain, range, uninterpolate, interpolate) {
    var u = uninterpolate(domain[0], domain[1]),
        i = interpolate(range[0], range[1]);
    return function(x) {
      return i(u(x));
    };
  }
  function d3_scale_polylinear(domain, range, uninterpolate, interpolate) {
    var u = [],
        i = [],
        j = 0,
        k = Math.min(domain.length, range.length) - 1;
  
    // Handle descending domains.
    if (domain[k] < domain[0]) {
      domain = domain.slice().reverse();
      range = range.slice().reverse();
    }
  
    while (++j <= k) {
      u.push(uninterpolate(domain[j - 1], domain[j]));
      i.push(interpolate(range[j - 1], range[j]));
    }
  
    return function(x) {
      var j = d3.bisect(domain, x, 1, k) - 1;
      return i[j](u[j](x));
    };
  }
  d3.scale.log = function() {
    return d3_scale_log(d3.scale.linear(), d3_scale_logp);
  };
  
  function d3_scale_log(linear, log) {
    var pow = log.pow;
  
    function scale(x) {
      return linear(log(x));
    }
  
    scale.invert = function(x) {
      return pow(linear.invert(x));
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return linear.domain().map(pow);
      log = x[0] < 0 ? d3_scale_logn : d3_scale_logp;
      pow = log.pow;
      linear.domain(x.map(log));
      return scale;
    };
  
    scale.nice = function() {
      linear.domain(d3_scale_nice(linear.domain(), d3_scale_niceDefault));
      return scale;
    };
  
    scale.ticks = function() {
      var extent = d3_scaleExtent(linear.domain()),
          ticks = [];
      if (extent.every(isFinite)) {
        var i = Math.floor(extent[0]),
            j = Math.ceil(extent[1]),
            u = pow(extent[0]),
            v = pow(extent[1]);
        if (log === d3_scale_logn) {
          ticks.push(pow(i));
          for (; i++ < j;) for (var k = 9; k > 0; k--) ticks.push(pow(i) * k);
        } else {
          for (; i < j; i++) for (var k = 1; k < 10; k++) ticks.push(pow(i) * k);
          ticks.push(pow(i));
        }
        for (i = 0; ticks[i] < u; i++) {} // strip small values
        for (j = ticks.length; ticks[j - 1] > v; j--) {} // strip big values
        ticks = ticks.slice(i, j);
      }
      return ticks;
    };
  
    scale.tickFormat = function(n, format) {
      if (arguments.length < 2) format = d3_scale_logFormat;
      if (arguments.length < 1) return format;
      var k = n / scale.ticks().length,
          f = log === d3_scale_logn ? (e = -1e-12, Math.floor) : (e = 1e-12, Math.ceil),
          e;
      return function(d) {
        return d / pow(f(log(d) + e)) < k ? format(d) : "";
      };
    };
  
    scale.copy = function() {
      return d3_scale_log(linear.copy(), log);
    };
  
    return d3_scale_linearRebind(scale, linear);
  }
  
  var d3_scale_logFormat = d3.format(".0e");
  
  function d3_scale_logp(x) {
    return Math.log(x < 0 ? 0 : x) / Math.LN10;
  }
  
  function d3_scale_logn(x) {
    return -Math.log(x > 0 ? 0 : -x) / Math.LN10;
  }
  
  d3_scale_logp.pow = function(x) {
    return Math.pow(10, x);
  };
  
  d3_scale_logn.pow = function(x) {
    return -Math.pow(10, -x);
  };
  d3.scale.pow = function() {
    return d3_scale_pow(d3.scale.linear(), 1);
  };
  
  function d3_scale_pow(linear, exponent) {
    var powp = d3_scale_powPow(exponent),
        powb = d3_scale_powPow(1 / exponent);
  
    function scale(x) {
      return linear(powp(x));
    }
  
    scale.invert = function(x) {
      return powb(linear.invert(x));
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return linear.domain().map(powb);
      linear.domain(x.map(powp));
      return scale;
    };
  
    scale.ticks = function(m) {
      return d3_scale_linearTicks(scale.domain(), m);
    };
  
    scale.tickFormat = function(m) {
      return d3_scale_linearTickFormat(scale.domain(), m);
    };
  
    scale.nice = function() {
      return scale.domain(d3_scale_nice(scale.domain(), d3_scale_linearNice));
    };
  
    scale.exponent = function(x) {
      if (!arguments.length) return exponent;
      var domain = scale.domain();
      powp = d3_scale_powPow(exponent = x);
      powb = d3_scale_powPow(1 / exponent);
      return scale.domain(domain);
    };
  
    scale.copy = function() {
      return d3_scale_pow(linear.copy(), exponent);
    };
  
    return d3_scale_linearRebind(scale, linear);
  }
  
  function d3_scale_powPow(e) {
    return function(x) {
      return x < 0 ? -Math.pow(-x, e) : Math.pow(x, e);
    };
  }
  d3.scale.sqrt = function() {
    return d3.scale.pow().exponent(.5);
  };
  d3.scale.ordinal = function() {
    return d3_scale_ordinal([], {t: "range", x: []});
  };
  
  function d3_scale_ordinal(domain, ranger) {
    var index,
        range,
        rangeBand;
  
    function scale(x) {
      return range[((index.get(x) || index.set(x, domain.push(x))) - 1) % range.length];
    }
  
    function steps(start, step) {
      return d3.range(domain.length).map(function(i) { return start + step * i; });
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = [];
      index = new d3_Map;
      var i = -1, n = x.length, xi;
      while (++i < n) if (!index.has(xi = x[i])) index.set(xi, domain.push(xi));
      return scale[ranger.t](ranger.x, ranger.p);
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      rangeBand = 0;
      ranger = {t: "range", x: x};
      return scale;
    };
  
    scale.rangePoints = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var start = x[0],
          stop = x[1],
          step = (stop - start) / (domain.length - 1 + padding);
      range = steps(domain.length < 2 ? (start + stop) / 2 : start + step * padding / 2, step);
      rangeBand = 0;
      ranger = {t: "rangePoints", x: x, p: padding};
      return scale;
    };
  
    scale.rangeBands = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var reverse = x[1] < x[0],
          start = x[reverse - 0],
          stop = x[1 - reverse],
          step = (stop - start) / (domain.length + padding);
      range = steps(start + step * padding, step);
      if (reverse) range.reverse();
      rangeBand = step * (1 - padding);
      ranger = {t: "rangeBands", x: x, p: padding};
      return scale;
    };
  
    scale.rangeRoundBands = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var reverse = x[1] < x[0],
          start = x[reverse - 0],
          stop = x[1 - reverse],
          step = Math.floor((stop - start) / (domain.length + padding)),
          error = stop - start - (domain.length - padding) * step;
      range = steps(start + Math.round(error / 2), step);
      if (reverse) range.reverse();
      rangeBand = Math.round(step * (1 - padding));
      ranger = {t: "rangeRoundBands", x: x, p: padding};
      return scale;
    };
  
    scale.rangeBand = function() {
      return rangeBand;
    };
  
    scale.rangeExtent = function() {
      return d3_scaleExtent(ranger.x);
    };
  
    scale.copy = function() {
      return d3_scale_ordinal(domain, ranger);
    };
  
    return scale.domain(domain);
  }
  /*
   * This product includes color specifications and designs developed by Cynthia
   * Brewer (http://colorbrewer.org/). See lib/colorbrewer for more information.
   */
  
  d3.scale.category10 = function() {
    return d3.scale.ordinal().range(d3_category10);
  };
  
  d3.scale.category20 = function() {
    return d3.scale.ordinal().range(d3_category20);
  };
  
  d3.scale.category20b = function() {
    return d3.scale.ordinal().range(d3_category20b);
  };
  
  d3.scale.category20c = function() {
    return d3.scale.ordinal().range(d3_category20c);
  };
  
  var d3_category10 = [
    "#1f77b4", "#ff7f0e", "#2ca02c", "#d62728", "#9467bd",
    "#8c564b", "#e377c2", "#7f7f7f", "#bcbd22", "#17becf"
  ];
  
  var d3_category20 = [
    "#1f77b4", "#aec7e8",
    "#ff7f0e", "#ffbb78",
    "#2ca02c", "#98df8a",
    "#d62728", "#ff9896",
    "#9467bd", "#c5b0d5",
    "#8c564b", "#c49c94",
    "#e377c2", "#f7b6d2",
    "#7f7f7f", "#c7c7c7",
    "#bcbd22", "#dbdb8d",
    "#17becf", "#9edae5"
  ];
  
  var d3_category20b = [
    "#393b79", "#5254a3", "#6b6ecf", "#9c9ede",
    "#637939", "#8ca252", "#b5cf6b", "#cedb9c",
    "#8c6d31", "#bd9e39", "#e7ba52", "#e7cb94",
    "#843c39", "#ad494a", "#d6616b", "#e7969c",
    "#7b4173", "#a55194", "#ce6dbd", "#de9ed6"
  ];
  
  var d3_category20c = [
    "#3182bd", "#6baed6", "#9ecae1", "#c6dbef",
    "#e6550d", "#fd8d3c", "#fdae6b", "#fdd0a2",
    "#31a354", "#74c476", "#a1d99b", "#c7e9c0",
    "#756bb1", "#9e9ac8", "#bcbddc", "#dadaeb",
    "#636363", "#969696", "#bdbdbd", "#d9d9d9"
  ];
  d3.scale.quantile = function() {
    return d3_scale_quantile([], []);
  };
  
  function d3_scale_quantile(domain, range) {
    var thresholds;
  
    function rescale() {
      var k = 0,
          n = domain.length,
          q = range.length;
      thresholds = [];
      while (++k < q) thresholds[k - 1] = d3.quantile(domain, k / q);
      return scale;
    }
  
    function scale(x) {
      if (isNaN(x = +x)) return NaN;
      return range[d3.bisect(thresholds, x)];
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = x.filter(function(d) { return !isNaN(d); }).sort(d3.ascending);
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.quantiles = function() {
      return thresholds;
    };
  
    scale.copy = function() {
      return d3_scale_quantile(domain, range); // copy on write!
    };
  
    return rescale();
  }
  d3.scale.quantize = function() {
    return d3_scale_quantize(0, 1, [0, 1]);
  };
  
  function d3_scale_quantize(x0, x1, range) {
    var kx, i;
  
    function scale(x) {
      return range[Math.max(0, Math.min(i, Math.floor(kx * (x - x0))))];
    }
  
    function rescale() {
      kx = range.length / (x1 - x0);
      i = range.length - 1;
      return scale;
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return [x0, x1];
      x0 = +x[0];
      x1 = +x[x.length - 1];
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.copy = function() {
      return d3_scale_quantize(x0, x1, range); // copy on write
    };
  
    return rescale();
  }
  d3.scale.identity = function() {
    return d3_scale_identity([0, 1]);
  };
  
  function d3_scale_identity(domain) {
  
    function identity(x) { return +x; }
  
    identity.invert = identity;
  
    identity.domain = identity.range = function(x) {
      if (!arguments.length) return domain;
      domain = x.map(identity);
      return identity;
    };
  
    identity.ticks = function(m) {
      return d3_scale_linearTicks(domain, m);
    };
  
    identity.tickFormat = function(m) {
      return d3_scale_linearTickFormat(domain, m);
    };
  
    identity.copy = function() {
      return d3_scale_identity(domain);
    };
  
    return identity;
  }
  d3.svg = {};
  d3.svg.arc = function() {
    var innerRadius = d3_svg_arcInnerRadius,
        outerRadius = d3_svg_arcOuterRadius,
        startAngle = d3_svg_arcStartAngle,
        endAngle = d3_svg_arcEndAngle;
  
    function arc() {
      var r0 = innerRadius.apply(this, arguments),
          r1 = outerRadius.apply(this, arguments),
          a0 = startAngle.apply(this, arguments) + d3_svg_arcOffset,
          a1 = endAngle.apply(this, arguments) + d3_svg_arcOffset,
          da = (a1 < a0 && (da = a0, a0 = a1, a1 = da), a1 - a0),
          df = da < Math.PI ? "0" : "1",
          c0 = Math.cos(a0),
          s0 = Math.sin(a0),
          c1 = Math.cos(a1),
          s1 = Math.sin(a1);
      return da >= d3_svg_arcMax
        ? (r0
        ? "M0," + r1
        + "A" + r1 + "," + r1 + " 0 1,1 0," + (-r1)
        + "A" + r1 + "," + r1 + " 0 1,1 0," + r1
        + "M0," + r0
        + "A" + r0 + "," + r0 + " 0 1,0 0," + (-r0)
        + "A" + r0 + "," + r0 + " 0 1,0 0," + r0
        + "Z"
        : "M0," + r1
        + "A" + r1 + "," + r1 + " 0 1,1 0," + (-r1)
        + "A" + r1 + "," + r1 + " 0 1,1 0," + r1
        + "Z")
        : (r0
        ? "M" + r1 * c0 + "," + r1 * s0
        + "A" + r1 + "," + r1 + " 0 " + df + ",1 " + r1 * c1 + "," + r1 * s1
        + "L" + r0 * c1 + "," + r0 * s1
        + "A" + r0 + "," + r0 + " 0 " + df + ",0 " + r0 * c0 + "," + r0 * s0
        + "Z"
        : "M" + r1 * c0 + "," + r1 * s0
        + "A" + r1 + "," + r1 + " 0 " + df + ",1 " + r1 * c1 + "," + r1 * s1
        + "L0,0"
        + "Z");
    }
  
    arc.innerRadius = function(v) {
      if (!arguments.length) return innerRadius;
      innerRadius = d3.functor(v);
      return arc;
    };
  
    arc.outerRadius = function(v) {
      if (!arguments.length) return outerRadius;
      outerRadius = d3.functor(v);
      return arc;
    };
  
    arc.startAngle = function(v) {
      if (!arguments.length) return startAngle;
      startAngle = d3.functor(v);
      return arc;
    };
  
    arc.endAngle = function(v) {
      if (!arguments.length) return endAngle;
      endAngle = d3.functor(v);
      return arc;
    };
  
    arc.centroid = function() {
      var r = (innerRadius.apply(this, arguments)
          + outerRadius.apply(this, arguments)) / 2,
          a = (startAngle.apply(this, arguments)
          + endAngle.apply(this, arguments)) / 2 + d3_svg_arcOffset;
      return [Math.cos(a) * r, Math.sin(a) * r];
    };
  
    return arc;
  };
  
  var d3_svg_arcOffset = -Math.PI / 2,
      d3_svg_arcMax = 2 * Math.PI - 1e-6;
  
  function d3_svg_arcInnerRadius(d) {
    return d.innerRadius;
  }
  
  function d3_svg_arcOuterRadius(d) {
    return d.outerRadius;
  }
  
  function d3_svg_arcStartAngle(d) {
    return d.startAngle;
  }
  
  function d3_svg_arcEndAngle(d) {
    return d.endAngle;
  }
  function d3_svg_line(projection) {
    var x = d3_svg_lineX,
        y = d3_svg_lineY,
        interpolate = d3_svg_lineInterpolatorDefault,
        interpolator = d3_svg_lineInterpolators.get(interpolate),
        tension = .7;
  
    function line(d) {
      return d.length < 1 ? null : "M" + interpolator(projection(d3_svg_linePoints(this, d, x, y)), tension);
    }
  
    line.x = function(v) {
      if (!arguments.length) return x;
      x = v;
      return line;
    };
  
    line.y = function(v) {
      if (!arguments.length) return y;
      y = v;
      return line;
    };
  
    line.interpolate = function(v) {
      if (!arguments.length) return interpolate;
      if (!d3_svg_lineInterpolators.has(v += "")) v = d3_svg_lineInterpolatorDefault;
      interpolator = d3_svg_lineInterpolators.get(interpolate = v);
      return line;
    };
  
    line.tension = function(v) {
      if (!arguments.length) return tension;
      tension = v;
      return line;
    };
  
    return line;
  }
  
  d3.svg.line = function() {
    return d3_svg_line(Object);
  };
  
  // Converts the specified array of data into an array of points
  // (x-y tuples), by evaluating the specified `x` and `y` functions on each
  // data point. The `this` context of the evaluated functions is the specified
  // "self" object; each function is passed the current datum and index.
  function d3_svg_linePoints(self, d, x, y) {
    var points = [],
        i = -1,
        n = d.length,
        fx = typeof x === "function",
        fy = typeof y === "function",
        value;
    if (fx && fy) {
      while (++i < n) points.push([
        x.call(self, value = d[i], i),
        y.call(self, value, i)
      ]);
    } else if (fx) {
      while (++i < n) points.push([x.call(self, d[i], i), y]);
    } else if (fy) {
      while (++i < n) points.push([x, y.call(self, d[i], i)]);
    } else {
      while (++i < n) points.push([x, y]);
    }
    return points;
  }
  
  // The default `x` property, which references d[0].
  function d3_svg_lineX(d) {
    return d[0];
  }
  
  // The default `y` property, which references d[1].
  function d3_svg_lineY(d) {
    return d[1];
  }
  
  var d3_svg_lineInterpolatorDefault = "linear";
  
  // The various interpolators supported by the `line` class.
  var d3_svg_lineInterpolators = d3.map({
    "linear": d3_svg_lineLinear,
    "step-before": d3_svg_lineStepBefore,
    "step-after": d3_svg_lineStepAfter,
    "basis": d3_svg_lineBasis,
    "basis-open": d3_svg_lineBasisOpen,
    "basis-closed": d3_svg_lineBasisClosed,
    "bundle": d3_svg_lineBundle,
    "cardinal": d3_svg_lineCardinal,
    "cardinal-open": d3_svg_lineCardinalOpen,
    "cardinal-closed": d3_svg_lineCardinalClosed,
    "monotone": d3_svg_lineMonotone
  });
  
  // Linear interpolation; generates "L" commands.
  function d3_svg_lineLinear(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("L", (p = points[i])[0], ",", p[1]);
    return path.join("");
  }
  
  // Step interpolation; generates "H" and "V" commands.
  function d3_svg_lineStepBefore(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("V", (p = points[i])[1], "H", p[0]);
    return path.join("");
  }
  
  // Step interpolation; generates "H" and "V" commands.
  function d3_svg_lineStepAfter(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("H", (p = points[i])[0], "V", p[1]);
    return path.join("");
  }
  
  // Open cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinalOpen(points, tension) {
    return points.length < 4
        ? d3_svg_lineLinear(points)
        : points[1] + d3_svg_lineHermite(points.slice(1, points.length - 1),
          d3_svg_lineCardinalTangents(points, tension));
  }
  
  // Closed cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinalClosed(points, tension) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] + d3_svg_lineHermite((points.push(points[0]), points),
          d3_svg_lineCardinalTangents([points[points.length - 2]]
          .concat(points, [points[1]]), tension));
  }
  
  // Cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinal(points, tension, closed) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] + d3_svg_lineHermite(points,
          d3_svg_lineCardinalTangents(points, tension));
  }
  
  // Hermite spline construction; generates "C" commands.
  function d3_svg_lineHermite(points, tangents) {
    if (tangents.length < 1
        || (points.length != tangents.length
        && points.length != tangents.length + 2)) {
      return d3_svg_lineLinear(points);
    }
  
    var quad = points.length != tangents.length,
        path = "",
        p0 = points[0],
        p = points[1],
        t0 = tangents[0],
        t = t0,
        pi = 1;
  
    if (quad) {
      path += "Q" + (p[0] - t0[0] * 2 / 3) + "," + (p[1] - t0[1] * 2 / 3)
          + "," + p[0] + "," + p[1];
      p0 = points[1];
      pi = 2;
    }
  
    if (tangents.length > 1) {
      t = tangents[1];
      p = points[pi];
      pi++;
      path += "C" + (p0[0] + t0[0]) + "," + (p0[1] + t0[1])
          + "," + (p[0] - t[0]) + "," + (p[1] - t[1])
          + "," + p[0] + "," + p[1];
      for (var i = 2; i < tangents.length; i++, pi++) {
        p = points[pi];
        t = tangents[i];
        path += "S" + (p[0] - t[0]) + "," + (p[1] - t[1])
            + "," + p[0] + "," + p[1];
      }
    }
  
    if (quad) {
      var lp = points[pi];
      path += "Q" + (p[0] + t[0] * 2 / 3) + "," + (p[1] + t[1] * 2 / 3)
          + "," + lp[0] + "," + lp[1];
    }
  
    return path;
  }
  
  // Generates tangents for a cardinal spline.
  function d3_svg_lineCardinalTangents(points, tension) {
    var tangents = [],
        a = (1 - tension) / 2,
        p0,
        p1 = points[0],
        p2 = points[1],
        i = 1,
        n = points.length;
    while (++i < n) {
      p0 = p1;
      p1 = p2;
      p2 = points[i];
      tangents.push([a * (p2[0] - p0[0]), a * (p2[1] - p0[1])]);
    }
    return tangents;
  }
  
  // B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasis(points) {
    if (points.length < 3) return d3_svg_lineLinear(points);
    var i = 1,
        n = points.length,
        pi = points[0],
        x0 = pi[0],
        y0 = pi[1],
        px = [x0, x0, x0, (pi = points[1])[0]],
        py = [y0, y0, y0, pi[1]],
        path = [x0, ",", y0];
    d3_svg_lineBasisBezier(path, px, py);
    while (++i < n) {
      pi = points[i];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    i = -1;
    while (++i < 2) {
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  // Open B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasisOpen(points) {
    if (points.length < 4) return d3_svg_lineLinear(points);
    var path = [],
        i = -1,
        n = points.length,
        pi,
        px = [0],
        py = [0];
    while (++i < 3) {
      pi = points[i];
      px.push(pi[0]);
      py.push(pi[1]);
    }
    path.push(d3_svg_lineDot4(d3_svg_lineBasisBezier3, px)
      + "," + d3_svg_lineDot4(d3_svg_lineBasisBezier3, py));
    --i; while (++i < n) {
      pi = points[i];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  // Closed B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasisClosed(points) {
    var path,
        i = -1,
        n = points.length,
        m = n + 4,
        pi,
        px = [],
        py = [];
    while (++i < 4) {
      pi = points[i % n];
      px.push(pi[0]);
      py.push(pi[1]);
    }
    path = [
      d3_svg_lineDot4(d3_svg_lineBasisBezier3, px), ",",
      d3_svg_lineDot4(d3_svg_lineBasisBezier3, py)
    ];
    --i; while (++i < m) {
      pi = points[i % n];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  function d3_svg_lineBundle(points, tension) {
    var n = points.length - 1,
        x0 = points[0][0],
        y0 = points[0][1],
        dx = points[n][0] - x0,
        dy = points[n][1] - y0,
        i = -1,
        p,
        t;
    while (++i <= n) {
      p = points[i];
      t = i / n;
      p[0] = tension * p[0] + (1 - tension) * (x0 + t * dx);
      p[1] = tension * p[1] + (1 - tension) * (y0 + t * dy);
    }
    return d3_svg_lineBasis(points);
  }
  
  // Returns the dot product of the given four-element vectors.
  function d3_svg_lineDot4(a, b) {
    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
  }
  
  // Matrix to transform basis (b-spline) control points to bezier
  // control points. Derived from FvD 11.2.8.
  var d3_svg_lineBasisBezier1 = [0, 2/3, 1/3, 0],
      d3_svg_lineBasisBezier2 = [0, 1/3, 2/3, 0],
      d3_svg_lineBasisBezier3 = [0, 1/6, 2/3, 1/6];
  
  // Pushes a "C" Bézier curve onto the specified path array, given the
  // two specified four-element arrays which define the control points.
  function d3_svg_lineBasisBezier(path, x, y) {
    path.push(
        "C", d3_svg_lineDot4(d3_svg_lineBasisBezier1, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier1, y),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier2, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier2, y),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier3, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier3, y));
  }
  
  // Computes the slope from points p0 to p1.
  function d3_svg_lineSlope(p0, p1) {
    return (p1[1] - p0[1]) / (p1[0] - p0[0]);
  }
  
  // Compute three-point differences for the given points.
  // http://en.wikipedia.org/wiki/Cubic_Hermite_spline#Finite_difference
  function d3_svg_lineFiniteDifferences(points) {
    var i = 0,
        j = points.length - 1,
        m = [],
        p0 = points[0],
        p1 = points[1],
        d = m[0] = d3_svg_lineSlope(p0, p1);
    while (++i < j) {
      m[i] = d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]));
    }
    m[i] = d;
    return m;
  }
  
  // Interpolates the given points using Fritsch-Carlson Monotone cubic Hermite
  // interpolation. Returns an array of tangent vectors. For details, see
  // http://en.wikipedia.org/wiki/Monotone_cubic_interpolation
  function d3_svg_lineMonotoneTangents(points) {
    var tangents = [],
        d,
        a,
        b,
        s,
        m = d3_svg_lineFiniteDifferences(points),
        i = -1,
        j = points.length - 1;
  
    // The first two steps are done by computing finite-differences:
    // 1. Compute the slopes of the secant lines between successive points.
    // 2. Initialize the tangents at every point as the average of the secants.
  
    // Then, for each segment…
    while (++i < j) {
      d = d3_svg_lineSlope(points[i], points[i + 1]);
  
      // 3. If two successive yk = y{k + 1} are equal (i.e., d is zero), then set
      // mk = m{k + 1} = 0 as the spline connecting these points must be flat to
      // preserve monotonicity. Ignore step 4 and 5 for those k.
  
      if (Math.abs(d) < 1e-6) {
        m[i] = m[i + 1] = 0;
      } else {
        // 4. Let ak = mk / dk and bk = m{k + 1} / dk.
        a = m[i] / d;
        b = m[i + 1] / d;
  
        // 5. Prevent overshoot and ensure monotonicity by restricting the
        // magnitude of vector <ak, bk> to a circle of radius 3.
        s = a * a + b * b;
        if (s > 9) {
          s = d * 3 / Math.sqrt(s);
          m[i] = s * a;
          m[i + 1] = s * b;
        }
      }
    }
  
    // Compute the normalized tangent vector from the slopes. Note that if x is
    // not monotonic, it's possible that the slope will be infinite, so we protect
    // against NaN by setting the coordinate to zero.
    i = -1; while (++i <= j) {
      s = (points[Math.min(j, i + 1)][0] - points[Math.max(0, i - 1)][0])
        / (6 * (1 + m[i] * m[i]));
      tangents.push([s || 0, m[i] * s || 0]);
    }
  
    return tangents;
  }
  
  function d3_svg_lineMonotone(points) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] +
          d3_svg_lineHermite(points, d3_svg_lineMonotoneTangents(points));
  }
  d3.svg.line.radial = function() {
    var line = d3_svg_line(d3_svg_lineRadial);
    line.radius = line.x, delete line.x;
    line.angle = line.y, delete line.y;
    return line;
  };
  
  function d3_svg_lineRadial(points) {
    var point,
        i = -1,
        n = points.length,
        r,
        a;
    while (++i < n) {
      point = points[i];
      r = point[0];
      a = point[1] + d3_svg_arcOffset;
      point[0] = r * Math.cos(a);
      point[1] = r * Math.sin(a);
    }
    return points;
  }
  function d3_svg_area(projection) {
    var x0 = d3_svg_lineX,
        x1 = d3_svg_lineX,
        y0 = 0,
        y1 = d3_svg_lineY,
        interpolate,
        i0,
        i1,
        tension = .7;
  
    function area(d) {
      if (d.length < 1) return null;
      var points0 = d3_svg_linePoints(this, d, x0, y0),
          points1 = d3_svg_linePoints(this, d, x0 === x1 ? d3_svg_areaX(points0) : x1, y0 === y1 ? d3_svg_areaY(points0) : y1);
      return "M" + i0(projection(points1), tension)
           + "L" + i1(projection(points0.reverse()), tension)
           + "Z";
    }
  
    area.x = function(x) {
      if (!arguments.length) return x1;
      x0 = x1 = x;
      return area;
    };
  
    area.x0 = function(x) {
      if (!arguments.length) return x0;
      x0 = x;
      return area;
    };
  
    area.x1 = function(x) {
      if (!arguments.length) return x1;
      x1 = x;
      return area;
    };
  
    area.y = function(y) {
      if (!arguments.length) return y1;
      y0 = y1 = y;
      return area;
    };
  
    area.y0 = function(y) {
      if (!arguments.length) return y0;
      y0 = y;
      return area;
    };
  
    area.y1 = function(y) {
      if (!arguments.length) return y1;
      y1 = y;
      return area;
    };
  
    area.interpolate = function(x) {
      if (!arguments.length) return interpolate;
      if (!d3_svg_lineInterpolators.has(x += "")) x = d3_svg_lineInterpolatorDefault;
      i0 = d3_svg_lineInterpolators.get(interpolate = x);
      i1 = i0.reverse || i0;
      return area;
    };
  
    area.tension = function(x) {
      if (!arguments.length) return tension;
      tension = x;
      return area;
    };
  
    return area.interpolate("linear");
  }
  
  d3_svg_lineStepBefore.reverse = d3_svg_lineStepAfter;
  d3_svg_lineStepAfter.reverse = d3_svg_lineStepBefore;
  
  d3.svg.area = function() {
    return d3_svg_area(Object);
  };
  
  function d3_svg_areaX(points) {
    return function(d, i) {
      return points[i][0];
    };
  }
  
  function d3_svg_areaY(points) {
    return function(d, i) {
      return points[i][1];
    };
  }
  d3.svg.area.radial = function() {
    var area = d3_svg_area(d3_svg_lineRadial);
    area.radius = area.x, delete area.x;
    area.innerRadius = area.x0, delete area.x0;
    area.outerRadius = area.x1, delete area.x1;
    area.angle = area.y, delete area.y;
    area.startAngle = area.y0, delete area.y0;
    area.endAngle = area.y1, delete area.y1;
    return area;
  };
  d3.svg.chord = function() {
    var source = d3_svg_chordSource,
        target = d3_svg_chordTarget,
        radius = d3_svg_chordRadius,
        startAngle = d3_svg_arcStartAngle,
        endAngle = d3_svg_arcEndAngle;
  
    // TODO Allow control point to be customized.
  
    function chord(d, i) {
      var s = subgroup(this, source, d, i),
          t = subgroup(this, target, d, i);
      return "M" + s.p0
        + arc(s.r, s.p1, s.a1 - s.a0) + (equals(s, t)
        ? curve(s.r, s.p1, s.r, s.p0)
        : curve(s.r, s.p1, t.r, t.p0)
        + arc(t.r, t.p1, t.a1 - t.a0)
        + curve(t.r, t.p1, s.r, s.p0))
        + "Z";
    }
  
    function subgroup(self, f, d, i) {
      var subgroup = f.call(self, d, i),
          r = radius.call(self, subgroup, i),
          a0 = startAngle.call(self, subgroup, i) + d3_svg_arcOffset,
          a1 = endAngle.call(self, subgroup, i) + d3_svg_arcOffset;
      return {
        r: r,
        a0: a0,
        a1: a1,
        p0: [r * Math.cos(a0), r * Math.sin(a0)],
        p1: [r * Math.cos(a1), r * Math.sin(a1)]
      };
    }
  
    function equals(a, b) {
      return a.a0 == b.a0 && a.a1 == b.a1;
    }
  
    function arc(r, p, a) {
      return "A" + r + "," + r + " 0 " + +(a > Math.PI) + ",1 " + p;
    }
  
    function curve(r0, p0, r1, p1) {
      return "Q 0,0 " + p1;
    }
  
    chord.radius = function(v) {
      if (!arguments.length) return radius;
      radius = d3.functor(v);
      return chord;
    };
  
    chord.source = function(v) {
      if (!arguments.length) return source;
      source = d3.functor(v);
      return chord;
    };
  
    chord.target = function(v) {
      if (!arguments.length) return target;
      target = d3.functor(v);
      return chord;
    };
  
    chord.startAngle = function(v) {
      if (!arguments.length) return startAngle;
      startAngle = d3.functor(v);
      return chord;
    };
  
    chord.endAngle = function(v) {
      if (!arguments.length) return endAngle;
      endAngle = d3.functor(v);
      return chord;
    };
  
    return chord;
  };
  
  function d3_svg_chordSource(d) {
    return d.source;
  }
  
  function d3_svg_chordTarget(d) {
    return d.target;
  }
  
  function d3_svg_chordRadius(d) {
    return d.radius;
  }
  
  function d3_svg_chordStartAngle(d) {
    return d.startAngle;
  }
  
  function d3_svg_chordEndAngle(d) {
    return d.endAngle;
  }
  d3.svg.diagonal = function() {
    var source = d3_svg_chordSource,
        target = d3_svg_chordTarget,
        projection = d3_svg_diagonalProjection;
  
    function diagonal(d, i) {
      var p0 = source.call(this, d, i),
          p3 = target.call(this, d, i),
          m = (p0.y + p3.y) / 2,
          p = [p0, {x: p0.x, y: m}, {x: p3.x, y: m}, p3];
      p = p.map(projection);
      return "M" + p[0] + "C" + p[1] + " " + p[2] + " " + p[3];
    }
  
    diagonal.source = function(x) {
      if (!arguments.length) return source;
      source = d3.functor(x);
      return diagonal;
    };
  
    diagonal.target = function(x) {
      if (!arguments.length) return target;
      target = d3.functor(x);
      return diagonal;
    };
  
    diagonal.projection = function(x) {
      if (!arguments.length) return projection;
      projection = x;
      return diagonal;
    };
  
    return diagonal;
  };
  
  function d3_svg_diagonalProjection(d) {
    return [d.x, d.y];
  }
  d3.svg.diagonal.radial = function() {
    var diagonal = d3.svg.diagonal(),
        projection = d3_svg_diagonalProjection,
        projection_ = diagonal.projection;
  
    diagonal.projection = function(x) {
      return arguments.length
          ? projection_(d3_svg_diagonalRadialProjection(projection = x))
          : projection;
    };
  
    return diagonal;
  };
  
  function d3_svg_diagonalRadialProjection(projection) {
    return function() {
      var d = projection.apply(this, arguments),
          r = d[0],
          a = d[1] + d3_svg_arcOffset;
      return [r * Math.cos(a), r * Math.sin(a)];
    };
  }
  d3.svg.mouse = d3.mouse;
  d3.svg.touches = d3.touches;
  d3.svg.symbol = function() {
    var type = d3_svg_symbolType,
        size = d3_svg_symbolSize;
  
    function symbol(d, i) {
      return (d3_svg_symbols.get(type.call(this, d, i))
          || d3_svg_symbolCircle)
          (size.call(this, d, i));
    }
  
    symbol.type = function(x) {
      if (!arguments.length) return type;
      type = d3.functor(x);
      return symbol;
    };
  
    // size of symbol in square pixels
    symbol.size = function(x) {
      if (!arguments.length) return size;
      size = d3.functor(x);
      return symbol;
    };
  
    return symbol;
  };
  
  function d3_svg_symbolSize() {
    return 64;
  }
  
  function d3_svg_symbolType() {
    return "circle";
  }
  
  function d3_svg_symbolCircle(size) {
    var r = Math.sqrt(size / Math.PI);
    return "M0," + r
        + "A" + r + "," + r + " 0 1,1 0," + (-r)
        + "A" + r + "," + r + " 0 1,1 0," + r
        + "Z";
  }
  
  // TODO cross-diagonal?
  var d3_svg_symbols = d3.map({
    "circle": d3_svg_symbolCircle,
    "cross": function(size) {
      var r = Math.sqrt(size / 5) / 2;
      return "M" + -3 * r + "," + -r
          + "H" + -r
          + "V" + -3 * r
          + "H" + r
          + "V" + -r
          + "H" + 3 * r
          + "V" + r
          + "H" + r
          + "V" + 3 * r
          + "H" + -r
          + "V" + r
          + "H" + -3 * r
          + "Z";
    },
    "diamond": function(size) {
      var ry = Math.sqrt(size / (2 * d3_svg_symbolTan30)),
          rx = ry * d3_svg_symbolTan30;
      return "M0," + -ry
          + "L" + rx + ",0"
          + " 0," + ry
          + " " + -rx + ",0"
          + "Z";
    },
    "square": function(size) {
      var r = Math.sqrt(size) / 2;
      return "M" + -r + "," + -r
          + "L" + r + "," + -r
          + " " + r + "," + r
          + " " + -r + "," + r
          + "Z";
    },
    "triangle-down": function(size) {
      var rx = Math.sqrt(size / d3_svg_symbolSqrt3),
          ry = rx * d3_svg_symbolSqrt3 / 2;
      return "M0," + ry
          + "L" + rx +"," + -ry
          + " " + -rx + "," + -ry
          + "Z";
    },
    "triangle-up": function(size) {
      var rx = Math.sqrt(size / d3_svg_symbolSqrt3),
          ry = rx * d3_svg_symbolSqrt3 / 2;
      return "M0," + -ry
          + "L" + rx +"," + ry
          + " " + -rx + "," + ry
          + "Z";
    }
  });
  
  d3.svg.symbolTypes = d3_svg_symbols.keys();
  
  var d3_svg_symbolSqrt3 = Math.sqrt(3),
      d3_svg_symbolTan30 = Math.tan(30 * Math.PI / 180);
  d3.svg.axis = function() {
    var scale = d3.scale.linear(),
        orient = "bottom",
        tickMajorSize = 6,
        tickMinorSize = 6,
        tickEndSize = 6,
        tickPadding = 3,
        tickArguments_ = [10],
        tickValues = null,
        tickFormat_,
        tickSubdivide = 0;
  
    function axis(g) {
      g.each(function() {
        var g = d3.select(this);
  
        // Ticks, or domain values for ordinal scales.
        var ticks = tickValues == null ? (scale.ticks ? scale.ticks.apply(scale, tickArguments_) : scale.domain()) : tickValues,
            tickFormat = tickFormat_ == null ? (scale.tickFormat ? scale.tickFormat.apply(scale, tickArguments_) : String) : tickFormat_;
  
        // Minor ticks.
        var subticks = d3_svg_axisSubdivide(scale, ticks, tickSubdivide),
            subtick = g.selectAll(".minor").data(subticks, String),
            subtickEnter = subtick.enter().insert("line", "g").attr("class", "tick minor").style("opacity", 1e-6),
            subtickExit = d3.transition(subtick.exit()).style("opacity", 1e-6).remove(),
            subtickUpdate = d3.transition(subtick).style("opacity", 1);
  
        // Major ticks.
        var tick = g.selectAll("g").data(ticks, String),
            tickEnter = tick.enter().insert("g", "path").style("opacity", 1e-6),
            tickExit = d3.transition(tick.exit()).style("opacity", 1e-6).remove(),
            tickUpdate = d3.transition(tick).style("opacity", 1),
            tickTransform;
  
        // Domain.
        var range = d3_scaleRange(scale),
            path = g.selectAll(".domain").data([0]),
            pathEnter = path.enter().append("path").attr("class", "domain"),
            pathUpdate = d3.transition(path);
  
        // Stash a snapshot of the new scale, and retrieve the old snapshot.
        var scale1 = scale.copy(),
            scale0 = this.__chart__ || scale1;
        this.__chart__ = scale1;
  
        tickEnter.append("line").attr("class", "tick");
        tickEnter.append("text");
        tickUpdate.select("text").text(tickFormat);
  
        switch (orient) {
          case "bottom": {
            tickTransform = d3_svg_axisX;
            subtickEnter.attr("y2", tickMinorSize);
            subtickUpdate.attr("x2", 0).attr("y2", tickMinorSize);
            tickEnter.select("line").attr("y2", tickMajorSize);
            tickEnter.select("text").attr("y", Math.max(tickMajorSize, 0) + tickPadding);
            tickUpdate.select("line").attr("x2", 0).attr("y2", tickMajorSize);
            tickUpdate.select("text").attr("x", 0).attr("y", Math.max(tickMajorSize, 0) + tickPadding).attr("dy", ".71em").attr("text-anchor", "middle");
            pathUpdate.attr("d", "M" + range[0] + "," + tickEndSize + "V0H" + range[1] + "V" + tickEndSize);
            break;
          }
          case "top": {
            tickTransform = d3_svg_axisX;
            subtickEnter.attr("y2", -tickMinorSize);
            subtickUpdate.attr("x2", 0).attr("y2", -tickMinorSize);
            tickEnter.select("line").attr("y2", -tickMajorSize);
            tickEnter.select("text").attr("y", -(Math.max(tickMajorSize, 0) + tickPadding));
            tickUpdate.select("line").attr("x2", 0).attr("y2", -tickMajorSize);
            tickUpdate.select("text").attr("x", 0).attr("y", -(Math.max(tickMajorSize, 0) + tickPadding)).attr("dy", "0em").attr("text-anchor", "middle");
            pathUpdate.attr("d", "M" + range[0] + "," + -tickEndSize + "V0H" + range[1] + "V" + -tickEndSize);
            break;
          }
          case "left": {
            tickTransform = d3_svg_axisY;
            subtickEnter.attr("x2", -tickMinorSize);
            subtickUpdate.attr("x2", -tickMinorSize).attr("y2", 0);
            tickEnter.select("line").attr("x2", -tickMajorSize);
            tickEnter.select("text").attr("x", -(Math.max(tickMajorSize, 0) + tickPadding));
            tickUpdate.select("line").attr("x2", -tickMajorSize).attr("y2", 0);
            tickUpdate.select("text").attr("x", -(Math.max(tickMajorSize, 0) + tickPadding)).attr("y", 0).attr("dy", ".32em").attr("text-anchor", "end");
            pathUpdate.attr("d", "M" + -tickEndSize + "," + range[0] + "H0V" + range[1] + "H" + -tickEndSize);
            break;
          }
          case "right": {
            tickTransform = d3_svg_axisY;
            subtickEnter.attr("x2", tickMinorSize);
            subtickUpdate.attr("x2", tickMinorSize).attr("y2", 0);
            tickEnter.select("line").attr("x2", tickMajorSize);
            tickEnter.select("text").attr("x", Math.max(tickMajorSize, 0) + tickPadding);
            tickUpdate.select("line").attr("x2", tickMajorSize).attr("y2", 0);
            tickUpdate.select("text").attr("x", Math.max(tickMajorSize, 0) + tickPadding).attr("y", 0).attr("dy", ".32em").attr("text-anchor", "start");
            pathUpdate.attr("d", "M" + tickEndSize + "," + range[0] + "H0V" + range[1] + "H" + tickEndSize);
            break;
          }
        }
  
        // For quantitative scales:
        // - enter new ticks from the old scale
        // - exit old ticks to the new scale
        if (scale.ticks) {
          tickEnter.call(tickTransform, scale0);
          tickUpdate.call(tickTransform, scale1);
          tickExit.call(tickTransform, scale1);
          subtickEnter.call(tickTransform, scale0);
          subtickUpdate.call(tickTransform, scale1);
          subtickExit.call(tickTransform, scale1);
        }
  
        // For ordinal scales:
        // - any entering ticks are undefined in the old scale
        // - any exiting ticks are undefined in the new scale
        // Therefore, we only need to transition updating ticks.
        else {
          var dx = scale1.rangeBand() / 2, x = function(d) { return scale1(d) + dx; };
          tickEnter.call(tickTransform, x);
          tickUpdate.call(tickTransform, x);
        }
      });
    }
  
    axis.scale = function(x) {
      if (!arguments.length) return scale;
      scale = x;
      return axis;
    };
  
    axis.orient = function(x) {
      if (!arguments.length) return orient;
      orient = x;
      return axis;
    };
  
    axis.ticks = function() {
      if (!arguments.length) return tickArguments_;
      tickArguments_ = arguments;
      return axis;
    };
  
    axis.tickValues = function(x) {
      if (!arguments.length) return tickValues;
      tickValues = x;
      return axis;
    };
  
    axis.tickFormat = function(x) {
      if (!arguments.length) return tickFormat_;
      tickFormat_ = x;
      return axis;
    };
  
    axis.tickSize = function(x, y, z) {
      if (!arguments.length) return tickMajorSize;
      var n = arguments.length - 1;
      tickMajorSize = +x;
      tickMinorSize = n > 1 ? +y : tickMajorSize;
      tickEndSize = n > 0 ? +arguments[n] : tickMajorSize;
      return axis;
    };
  
    axis.tickPadding = function(x) {
      if (!arguments.length) return tickPadding;
      tickPadding = +x;
      return axis;
    };
  
    axis.tickSubdivide = function(x) {
      if (!arguments.length) return tickSubdivide;
      tickSubdivide = +x;
      return axis;
    };
  
    return axis;
  };
  
  function d3_svg_axisX(selection, x) {
    selection.attr("transform", function(d) { return "translate(" + x(d) + ",0)"; });
  }
  
  function d3_svg_axisY(selection, y) {
    selection.attr("transform", function(d) { return "translate(0," + y(d) + ")"; });
  }
  
  function d3_svg_axisSubdivide(scale, ticks, m) {
    subticks = [];
    if (m && ticks.length > 1) {
      var extent = d3_scaleExtent(scale.domain()),
          subticks,
          i = -1,
          n = ticks.length,
          d = (ticks[1] - ticks[0]) / ++m,
          j,
          v;
      while (++i < n) {
        for (j = m; --j > 0;) {
          if ((v = +ticks[i] - j * d) >= extent[0]) {
            subticks.push(v);
          }
        }
      }
      for (--i, j = 0; ++j < m && (v = +ticks[i] + j * d) < extent[1];) {
        subticks.push(v);
      }
    }
    return subticks;
  }
  d3.svg.brush = function() {
    var event = d3_eventDispatch(brush, "brushstart", "brush", "brushend"),
        x = null, // x-scale, optional
        y = null, // y-scale, optional
        resizes = d3_svg_brushResizes[0],
        extent = [[0, 0], [0, 0]], // [x0, y0], [x1, y1], in pixels (integers)
        extentDomain; // the extent in data space, lazily created
  
    function brush(g) {
      g.each(function() {
        var g = d3.select(this),
            bg = g.selectAll(".background").data([0]),
            fg = g.selectAll(".extent").data([0]),
            tz = g.selectAll(".resize").data(resizes, String),
            e;
  
        // Prepare the brush container for events.
        g
            .style("pointer-events", "all")
            .on("mousedown.brush", brushstart)
            .on("touchstart.brush", brushstart);
  
        // An invisible, mouseable area for starting a new brush.
        bg.enter().append("rect")
            .attr("class", "background")
            .style("visibility", "hidden")
            .style("cursor", "crosshair");
  
        // The visible brush extent; style this as you like!
        fg.enter().append("rect")
            .attr("class", "extent")
            .style("cursor", "move");
  
        // More invisible rects for resizing the extent.
        tz.enter().append("g")
            .attr("class", function(d) { return "resize " + d; })
            .style("cursor", function(d) { return d3_svg_brushCursor[d]; })
          .append("rect")
            .attr("x", function(d) { return /[ew]$/.test(d) ? -3 : null; })
            .attr("y", function(d) { return /^[ns]/.test(d) ? -3 : null; })
            .attr("width", 6)
            .attr("height", 6)
            .style("visibility", "hidden");
  
        // Show or hide the resizers.
        tz.style("display", brush.empty() ? "none" : null);
  
        // Remove any superfluous resizers.
        tz.exit().remove();
  
        // Initialize the background to fill the defined range.
        // If the range isn't defined, you can post-process.
        if (x) {
          e = d3_scaleRange(x);
          bg.attr("x", e[0]).attr("width", e[1] - e[0]);
          redrawX(g);
        }
        if (y) {
          e = d3_scaleRange(y);
          bg.attr("y", e[0]).attr("height", e[1] - e[0]);
          redrawY(g);
        }
        redraw(g);
      });
    }
  
    function redraw(g) {
      g.selectAll(".resize").attr("transform", function(d) {
        return "translate(" + extent[+/e$/.test(d)][0] + "," + extent[+/^s/.test(d)][1] + ")";
      });
    }
  
    function redrawX(g) {
      g.select(".extent").attr("x", extent[0][0]);
      g.selectAll(".extent,.n>rect,.s>rect").attr("width", extent[1][0] - extent[0][0]);
    }
  
    function redrawY(g) {
      g.select(".extent").attr("y", extent[0][1]);
      g.selectAll(".extent,.e>rect,.w>rect").attr("height", extent[1][1] - extent[0][1]);
    }
  
    function brushstart() {
      var target = this,
          eventTarget = d3.select(d3.event.target),
          event_ = event.of(target, arguments),
          g = d3.select(target),
          resizing = eventTarget.datum(),
          resizingX = !/^(n|s)$/.test(resizing) && x,
          resizingY = !/^(e|w)$/.test(resizing) && y,
          dragging = eventTarget.classed("extent"),
          center,
          origin = mouse(),
          offset;
  
      var w = d3.select(window)
          .on("mousemove.brush", brushmove)
          .on("mouseup.brush", brushend)
          .on("touchmove.brush", brushmove)
          .on("touchend.brush", brushend)
          .on("keydown.brush", keydown)
          .on("keyup.brush", keyup);
  
      // If the extent was clicked on, drag rather than brush;
      // store the point between the mouse and extent origin instead.
      if (dragging) {
        origin[0] = extent[0][0] - origin[0];
        origin[1] = extent[0][1] - origin[1];
      }
  
      // If a resizer was clicked on, record which side is to be resized.
      // Also, set the origin to the opposite side.
      else if (resizing) {
        var ex = +/w$/.test(resizing),
            ey = +/^n/.test(resizing);
        offset = [extent[1 - ex][0] - origin[0], extent[1 - ey][1] - origin[1]];
        origin[0] = extent[ex][0];
        origin[1] = extent[ey][1];
      }
  
      // If the ALT key is down when starting a brush, the center is at the mouse.
      else if (d3.event.altKey) center = origin.slice();
  
      // Propagate the active cursor to the body for the drag duration.
      g.style("pointer-events", "none").selectAll(".resize").style("display", null);
      d3.select("body").style("cursor", eventTarget.style("cursor"));
  
      // Notify listeners.
      event_({type: "brushstart"});
      brushmove();
      d3_eventCancel();
  
      function mouse() {
        var touches = d3.event.changedTouches;
        return touches ? d3.touches(target, touches)[0] : d3.mouse(target);
      }
  
      function keydown() {
        if (d3.event.keyCode == 32) {
          if (!dragging) {
            center = null;
            origin[0] -= extent[1][0];
            origin[1] -= extent[1][1];
            dragging = 2;
          }
          d3_eventCancel();
        }
      }
  
      function keyup() {
        if (d3.event.keyCode == 32 && dragging == 2) {
          origin[0] += extent[1][0];
          origin[1] += extent[1][1];
          dragging = 0;
          d3_eventCancel();
        }
      }
  
      function brushmove() {
        var point = mouse(),
            moved = false;
  
        // Preserve the offset for thick resizers.
        if (offset) {
          point[0] += offset[0];
          point[1] += offset[1];
        }
  
        if (!dragging) {
  
          // If needed, determine the center from the current extent.
          if (d3.event.altKey) {
            if (!center) center = [(extent[0][0] + extent[1][0]) / 2, (extent[0][1] + extent[1][1]) / 2];
  
            // Update the origin, for when the ALT key is released.
            origin[0] = extent[+(point[0] < center[0])][0];
            origin[1] = extent[+(point[1] < center[1])][1];
          }
  
          // When the ALT key is released, we clear the center.
          else center = null;
        }
  
        // Update the brush extent for each dimension.
        if (resizingX && move1(point, x, 0)) {
          redrawX(g);
          moved = true;
        }
        if (resizingY && move1(point, y, 1)) {
          redrawY(g);
          moved = true;
        }
  
        // Final redraw and notify listeners.
        if (moved) {
          redraw(g);
          event_({type: "brush", mode: dragging ? "move" : "resize"});
        }
      }
  
      function move1(point, scale, i) {
        var range = d3_scaleRange(scale),
            r0 = range[0],
            r1 = range[1],
            position = origin[i],
            size = extent[1][i] - extent[0][i],
            min,
            max;
  
        // When dragging, reduce the range by the extent size and position.
        if (dragging) {
          r0 -= position;
          r1 -= size + position;
        }
  
        // Clamp the point so that the extent fits within the range extent.
        min = Math.max(r0, Math.min(r1, point[i]));
  
        // Compute the new extent bounds.
        if (dragging) {
          max = (min += position) + size;
        } else {
  
          // If the ALT key is pressed, then preserve the center of the extent.
          if (center) position = Math.max(r0, Math.min(r1, 2 * center[i] - min));
  
          // Compute the min and max of the position and point.
          if (position < min) {
            max = min;
            min = position;
          } else {
            max = position;
          }
        }
  
        // Update the stored bounds.
        if (extent[0][i] !== min || extent[1][i] !== max) {
          extentDomain = null;
          extent[0][i] = min;
          extent[1][i] = max;
          return true;
        }
      }
  
      function brushend() {
        brushmove();
  
        // reset the cursor styles
        g.style("pointer-events", "all").selectAll(".resize").style("display", brush.empty() ? "none" : null);
        d3.select("body").style("cursor", null);
  
        w .on("mousemove.brush", null)
          .on("mouseup.brush", null)
          .on("touchmove.brush", null)
          .on("touchend.brush", null)
          .on("keydown.brush", null)
          .on("keyup.brush", null);
  
        event_({type: "brushend"});
        d3_eventCancel();
      }
    }
  
    brush.x = function(z) {
      if (!arguments.length) return x;
      x = z;
      resizes = d3_svg_brushResizes[!x << 1 | !y]; // fore!
      return brush;
    };
  
    brush.y = function(z) {
      if (!arguments.length) return y;
      y = z;
      resizes = d3_svg_brushResizes[!x << 1 | !y]; // fore!
      return brush;
    };
  
    brush.extent = function(z) {
      var x0, x1, y0, y1, t;
  
      // Invert the pixel extent to data-space.
      if (!arguments.length) {
        z = extentDomain || extent;
        if (x) {
          x0 = z[0][0], x1 = z[1][0];
          if (!extentDomain) {
            x0 = extent[0][0], x1 = extent[1][0];
            if (x.invert) x0 = x.invert(x0), x1 = x.invert(x1);
            if (x1 < x0) t = x0, x0 = x1, x1 = t;
          }
        }
        if (y) {
          y0 = z[0][1], y1 = z[1][1];
          if (!extentDomain) {
            y0 = extent[0][1], y1 = extent[1][1];
            if (y.invert) y0 = y.invert(y0), y1 = y.invert(y1);
            if (y1 < y0) t = y0, y0 = y1, y1 = t;
          }
        }
        return x && y ? [[x0, y0], [x1, y1]] : x ? [x0, x1] : y && [y0, y1];
      }
  
      // Scale the data-space extent to pixels.
      extentDomain = [[0, 0], [0, 0]];
      if (x) {
        x0 = z[0], x1 = z[1];
        if (y) x0 = x0[0], x1 = x1[0];
        extentDomain[0][0] = x0, extentDomain[1][0] = x1;
        if (x.invert) x0 = x(x0), x1 = x(x1);
        if (x1 < x0) t = x0, x0 = x1, x1 = t;
        extent[0][0] = x0 | 0, extent[1][0] = x1 | 0;
      }
      if (y) {
        y0 = z[0], y1 = z[1];
        if (x) y0 = y0[1], y1 = y1[1];
        extentDomain[0][1] = y0, extentDomain[1][1] = y1;
        if (y.invert) y0 = y(y0), y1 = y(y1);
        if (y1 < y0) t = y0, y0 = y1, y1 = t;
        extent[0][1] = y0 | 0, extent[1][1] = y1 | 0;
      }
  
      return brush;
    };
  
    brush.clear = function() {
      extentDomain = null;
      extent[0][0] =
      extent[0][1] =
      extent[1][0] =
      extent[1][1] = 0;
      return brush;
    };
  
    brush.empty = function() {
      return (x && extent[0][0] === extent[1][0])
          || (y && extent[0][1] === extent[1][1]);
    };
  
    return d3.rebind(brush, event, "on");
  };
  
  var d3_svg_brushCursor = {
    n: "ns-resize",
    e: "ew-resize",
    s: "ns-resize",
    w: "ew-resize",
    nw: "nwse-resize",
    ne: "nesw-resize",
    se: "nwse-resize",
    sw: "nesw-resize"
  };
  
  var d3_svg_brushResizes = [
    ["n", "e", "s", "w", "nw", "ne", "se", "sw"],
    ["e", "w"],
    ["n", "s"],
    []
  ];
  d3.behavior = {};
  // TODO Track touch points by identifier.
  
  d3.behavior.drag = function() {
    var event = d3_eventDispatch(drag, "drag", "dragstart", "dragend"),
        origin = null;
  
    function drag() {
      this.on("mousedown.drag", mousedown)
          .on("touchstart.drag", mousedown);
    }
  
    function mousedown() {
      var target = this,
          event_ = event.of(target, arguments),
          eventTarget = d3.event.target,
          offset,
          origin_ = point(),
          moved = 0;
  
      var w = d3.select(window)
          .on("mousemove.drag", dragmove)
          .on("touchmove.drag", dragmove)
          .on("mouseup.drag", dragend, true)
          .on("touchend.drag", dragend, true);
  
      if (origin) {
        offset = origin.apply(target, arguments);
        offset = [offset.x - origin_[0], offset.y - origin_[1]];
      } else {
        offset = [0, 0];
      }
  
      event_({type: "dragstart"});
  
      function point() {
        var p = target.parentNode,
            t = d3.event.changedTouches;
        return t ? d3.touches(p, t)[0] : d3.mouse(p);
      }
  
      function dragmove() {
        if (!target.parentNode) return dragend(); // target removed from DOM
  
        var p = point(),
            dx = p[0] - origin_[0],
            dy = p[1] - origin_[1];
  
        moved |= dx | dy;
        origin_ = p;
        d3_eventCancel();
  
        event_({type: "drag", x: p[0] + offset[0], y: p[1] + offset[1], dx: dx, dy: dy});
      }
  
      function dragend() {
        event_({type: "dragend"});
  
        // if moved, prevent the mouseup (and possibly click) from propagating
        if (moved) {
          d3_eventCancel();
          if (d3.event.target === eventTarget) w.on("click.drag", click, true);
        }
  
        w .on("mousemove.drag", null)
          .on("touchmove.drag", null)
          .on("mouseup.drag", null)
          .on("touchend.drag", null);
      }
  
      // prevent the subsequent click from propagating (e.g., for anchors)
      function click() {
        d3_eventCancel();
        w.on("click.drag", null);
      }
    }
  
    drag.origin = function(x) {
      if (!arguments.length) return origin;
      origin = x;
      return drag;
    };
  
    return d3.rebind(drag, event, "on");
  };
  d3.behavior.zoom = function() {
    var translate = [0, 0],
        translate0, // translate when we started zooming (to avoid drift)
        scale = 1,
        scale0, // scale when we started touching
        scaleExtent = d3_behavior_zoomInfinity,
        event = d3_eventDispatch(zoom, "zoom"),
        x0,
        x1,
        y0,
        y1,
        touchtime; // time of last touchstart (to detect double-tap)
  
    function zoom() {
      this
          .on("mousedown.zoom", mousedown)
          .on("mousewheel.zoom", mousewheel)
          .on("mousemove.zoom", mousemove)
          .on("DOMMouseScroll.zoom", mousewheel)
          .on("dblclick.zoom", dblclick)
          .on("touchstart.zoom", touchstart)
          .on("touchmove.zoom", touchmove)
          .on("touchend.zoom", touchstart);
    }
  
    zoom.translate = function(x) {
      if (!arguments.length) return translate;
      translate = x.map(Number);
      return zoom;
    };
  
    zoom.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return zoom;
    };
  
    zoom.scaleExtent = function(x) {
      if (!arguments.length) return scaleExtent;
      scaleExtent = x == null ? d3_behavior_zoomInfinity : x.map(Number);
      return zoom;
    };
  
    zoom.x = function(z) {
      if (!arguments.length) return x1;
      x1 = z;
      x0 = z.copy();
      return zoom;
    };
  
    zoom.y = function(z) {
      if (!arguments.length) return y1;
      y1 = z;
      y0 = z.copy();
      return zoom;
    };
  
    function location(p) {
      return [(p[0] - translate[0]) / scale, (p[1] - translate[1]) / scale];
    }
  
    function point(l) {
      return [l[0] * scale + translate[0], l[1] * scale + translate[1]];
    }
  
    function scaleTo(s) {
      scale = Math.max(scaleExtent[0], Math.min(scaleExtent[1], s));
    }
  
    function translateTo(p, l) {
      l = point(l);
      translate[0] += p[0] - l[0];
      translate[1] += p[1] - l[1];
    }
  
    function dispatch(event) {
      if (x1) x1.domain(x0.range().map(function(x) { return (x - translate[0]) / scale; }).map(x0.invert));
      if (y1) y1.domain(y0.range().map(function(y) { return (y - translate[1]) / scale; }).map(y0.invert));
      d3.event.preventDefault();
      event({type: "zoom", scale: scale, translate: translate});
    }
  
    function mousedown() {
      var target = this,
          event_ = event.of(target, arguments),
          eventTarget = d3.event.target,
          moved = 0,
          w = d3.select(window).on("mousemove.zoom", mousemove).on("mouseup.zoom", mouseup),
          l = location(d3.mouse(target));
  
      window.focus();
      d3_eventCancel();
  
      function mousemove() {
        moved = 1;
        translateTo(d3.mouse(target), l);
        dispatch(event_);
      }
  
      function mouseup() {
        if (moved) d3_eventCancel();
        w.on("mousemove.zoom", null).on("mouseup.zoom", null);
        if (moved && d3.event.target === eventTarget) w.on("click.zoom", click);
      }
  
      function click() {
        d3_eventCancel();
        w.on("click.zoom", null);
      }
    }
  
    function mousewheel() {
      if (!translate0) translate0 = location(d3.mouse(this));
      scaleTo(Math.pow(2, d3_behavior_zoomDelta() * .002) * scale);
      translateTo(d3.mouse(this), translate0);
      dispatch(event.of(this, arguments));
    }
  
    function mousemove() {
      translate0 = null;
    }
  
    function dblclick() {
      var p = d3.mouse(this), l = location(p);
      scaleTo(d3.event.shiftKey ? scale / 2 : scale * 2);
      translateTo(p, l);
      dispatch(event.of(this, arguments));
    }
  
    function touchstart() {
      var touches = d3.touches(this),
          now = Date.now();
  
      scale0 = scale;
      translate0 = {};
      touches.forEach(function(t) { translate0[t.identifier] = location(t); });
      d3_eventCancel();
  
      if ((touches.length === 1) && (now - touchtime < 500)) { // dbltap
        var p = touches[0], l = location(touches[0]);
        scaleTo(scale * 2);
        translateTo(p, l);
        dispatch(event.of(this, arguments));
      }
      touchtime = now;
    }
  
    function touchmove() {
      var touches = d3.touches(this),
          p0 = touches[0],
          l0 = translate0[p0.identifier];
      if (p1 = touches[1]) {
        var p1, l1 = translate0[p1.identifier];
        p0 = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
        l0 = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
        scaleTo(d3.event.scale * scale0);
      }
      translateTo(p0, l0);
      dispatch(event.of(this, arguments));
    }
  
    return d3.rebind(zoom, event, "on");
  };
  
  var d3_behavior_zoomDiv, // for interpreting mousewheel events
      d3_behavior_zoomInfinity = [0, Infinity]; // default scale extent
  
  function d3_behavior_zoomDelta() {
  
    // mousewheel events are totally broken!
    // https://bugs.webkit.org/show_bug.cgi?id=40441
    // not only that, but Chrome and Safari differ in re. to acceleration!
    if (!d3_behavior_zoomDiv) {
      d3_behavior_zoomDiv = d3.select("body").append("div")
          .style("visibility", "hidden")
          .style("top", 0)
          .style("height", 0)
          .style("width", 0)
          .style("overflow-y", "scroll")
        .append("div")
          .style("height", "2000px")
        .node().parentNode;
    }
  
    var e = d3.event, delta;
    try {
      d3_behavior_zoomDiv.scrollTop = 1000;
      d3_behavior_zoomDiv.dispatchEvent(e);
      delta = 1000 - d3_behavior_zoomDiv.scrollTop;
    } catch (error) {
      delta = e.wheelDelta || (-e.detail * 5);
    }
  
    return delta;
  }
  d3.layout = {};
  // Implements hierarchical edge bundling using Holten's algorithm. For each
  // input link, a path is computed that travels through the tree, up the parent
  // hierarchy to the least common ancestor, and then back down to the destination
  // node. Each path is simply an array of nodes.
  d3.layout.bundle = function() {
    return function(links) {
      var paths = [],
          i = -1,
          n = links.length;
      while (++i < n) paths.push(d3_layout_bundlePath(links[i]));
      return paths;
    };
  };
  
  function d3_layout_bundlePath(link) {
    var start = link.source,
        end = link.target,
        lca = d3_layout_bundleLeastCommonAncestor(start, end),
        points = [start];
    while (start !== lca) {
      start = start.parent;
      points.push(start);
    }
    var k = points.length;
    while (end !== lca) {
      points.splice(k, 0, end);
      end = end.parent;
    }
    return points;
  }
  
  function d3_layout_bundleAncestors(node) {
    var ancestors = [],
        parent = node.parent;
    while (parent != null) {
      ancestors.push(node);
      node = parent;
      parent = parent.parent;
    }
    ancestors.push(node);
    return ancestors;
  }
  
  function d3_layout_bundleLeastCommonAncestor(a, b) {
    if (a === b) return a;
    var aNodes = d3_layout_bundleAncestors(a),
        bNodes = d3_layout_bundleAncestors(b),
        aNode = aNodes.pop(),
        bNode = bNodes.pop(),
        sharedNode = null;
    while (aNode === bNode) {
      sharedNode = aNode;
      aNode = aNodes.pop();
      bNode = bNodes.pop();
    }
    return sharedNode;
  }
  d3.layout.chord = function() {
    var chord = {},
        chords,
        groups,
        matrix,
        n,
        padding = 0,
        sortGroups,
        sortSubgroups,
        sortChords;
  
    function relayout() {
      var subgroups = {},
          groupSums = [],
          groupIndex = d3.range(n),
          subgroupIndex = [],
          k,
          x,
          x0,
          i,
          j;
  
      chords = [];
      groups = [];
  
      // Compute the sum.
      k = 0, i = -1; while (++i < n) {
        x = 0, j = -1; while (++j < n) {
          x += matrix[i][j];
        }
        groupSums.push(x);
        subgroupIndex.push(d3.range(n));
        k += x;
      }
  
      // Sort groups…
      if (sortGroups) {
        groupIndex.sort(function(a, b) {
          return sortGroups(groupSums[a], groupSums[b]);
        });
      }
  
      // Sort subgroups…
      if (sortSubgroups) {
        subgroupIndex.forEach(function(d, i) {
          d.sort(function(a, b) {
            return sortSubgroups(matrix[i][a], matrix[i][b]);
          });
        });
      }
  
      // Convert the sum to scaling factor for [0, 2pi].
      // TODO Allow start and end angle to be specified.
      // TODO Allow padding to be specified as percentage?
      k = (2 * Math.PI - padding * n) / k;
  
      // Compute the start and end angle for each group and subgroup.
      // Note: Opera has a bug reordering object literal properties!
      x = 0, i = -1; while (++i < n) {
        x0 = x, j = -1; while (++j < n) {
          var di = groupIndex[i],
              dj = subgroupIndex[di][j],
              v = matrix[di][dj],
              a0 = x,
              a1 = x += v * k;
          subgroups[di + "-" + dj] = {
            index: di,
            subindex: dj,
            startAngle: a0,
            endAngle: a1,
            value: v
          };
        }
        groups.push({
          index: di,
          startAngle: x0,
          endAngle: x,
          value: (x - x0) / k
        });
        x += padding;
      }
  
      // Generate chords for each (non-empty) subgroup-subgroup link.
      i = -1; while (++i < n) {
        j = i - 1; while (++j < n) {
          var source = subgroups[i + "-" + j],
              target = subgroups[j + "-" + i];
          if (source.value || target.value) {
            chords.push(source.value < target.value
                ? {source: target, target: source}
                : {source: source, target: target});
          }
        }
      }
  
      if (sortChords) resort();
    }
  
    function resort() {
      chords.sort(function(a, b) {
        return sortChords(
            (a.source.value + a.target.value) / 2,
            (b.source.value + b.target.value) / 2);
      });
    }
  
    chord.matrix = function(x) {
      if (!arguments.length) return matrix;
      n = (matrix = x) && matrix.length;
      chords = groups = null;
      return chord;
    };
  
    chord.padding = function(x) {
      if (!arguments.length) return padding;
      padding = x;
      chords = groups = null;
      return chord;
    };
  
    chord.sortGroups = function(x) {
      if (!arguments.length) return sortGroups;
      sortGroups = x;
      chords = groups = null;
      return chord;
    };
  
    chord.sortSubgroups = function(x) {
      if (!arguments.length) return sortSubgroups;
      sortSubgroups = x;
      chords = null;
      return chord;
    };
  
    chord.sortChords = function(x) {
      if (!arguments.length) return sortChords;
      sortChords = x;
      if (chords) resort();
      return chord;
    };
  
    chord.chords = function() {
      if (!chords) relayout();
      return chords;
    };
  
    chord.groups = function() {
      if (!groups) relayout();
      return groups;
    };
  
    return chord;
  };
  // A rudimentary force layout using Gauss-Seidel.
  d3.layout.force = function() {
    var force = {},
        event = d3.dispatch("start", "tick", "end"),
        size = [1, 1],
        drag,
        alpha,
        friction = .9,
        linkDistance = d3_layout_forceLinkDistance,
        linkStrength = d3_layout_forceLinkStrength,
        charge = -30,
        gravity = .1,
        theta = .8,
        interval,
        nodes = [],
        links = [],
        distances,
        strengths,
        charges;
  
    function repulse(node) {
      return function(quad, x1, y1, x2, y2) {
        if (quad.point !== node) {
          var dx = quad.cx - node.x,
              dy = quad.cy - node.y,
              dn = 1 / Math.sqrt(dx * dx + dy * dy);
  
          /* Barnes-Hut criterion. */
          if ((x2 - x1) * dn < theta) {
            var k = quad.charge * dn * dn;
            node.px -= dx * k;
            node.py -= dy * k;
            return true;
          }
  
          if (quad.point && isFinite(dn)) {
            var k = quad.pointCharge * dn * dn;
            node.px -= dx * k;
            node.py -= dy * k;
          }
        }
        return !quad.charge;
      };
    }
  
    force.tick = function() {
      // simulated annealing, basically
      if ((alpha *= .99) < .005) {
        event.end({type: "end", alpha: alpha = 0});
        return true;
      }
  
      var n = nodes.length,
          m = links.length,
          q,
          i, // current index
          o, // current object
          s, // current source
          t, // current target
          l, // current distance
          k, // current force
          x, // x-distance
          y; // y-distance
  
      // gauss-seidel relaxation for links
      for (i = 0; i < m; ++i) {
        o = links[i];
        s = o.source;
        t = o.target;
        x = t.x - s.x;
        y = t.y - s.y;
        if (l = (x * x + y * y)) {
          l = alpha * strengths[i] * ((l = Math.sqrt(l)) - distances[i]) / l;
          x *= l;
          y *= l;
          t.x -= x * (k = s.weight / (t.weight + s.weight));
          t.y -= y * k;
          s.x += x * (k = 1 - k);
          s.y += y * k;
        }
      }
  
      // apply gravity forces
      if (k = alpha * gravity) {
        x = size[0] / 2;
        y = size[1] / 2;
        i = -1; if (k) while (++i < n) {
          o = nodes[i];
          o.x += (x - o.x) * k;
          o.y += (y - o.y) * k;
        }
      }
  
      // compute quadtree center of mass and apply charge forces
      if (charge) {
        d3_layout_forceAccumulate(q = d3.geom.quadtree(nodes), alpha, charges);
        i = -1; while (++i < n) {
          if (!(o = nodes[i]).fixed) {
            q.visit(repulse(o));
          }
        }
      }
  
      // position verlet integration
      i = -1; while (++i < n) {
        o = nodes[i];
        if (o.fixed) {
          o.x = o.px;
          o.y = o.py;
        } else {
          o.x -= (o.px - (o.px = o.x)) * friction;
          o.y -= (o.py - (o.py = o.y)) * friction;
        }
      }
  
      event.tick({type: "tick", alpha: alpha});
    };
  
    force.nodes = function(x) {
      if (!arguments.length) return nodes;
      nodes = x;
      return force;
    };
  
    force.links = function(x) {
      if (!arguments.length) return links;
      links = x;
      return force;
    };
  
    force.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return force;
    };
  
    force.linkDistance = function(x) {
      if (!arguments.length) return linkDistance;
      linkDistance = d3.functor(x);
      return force;
    };
  
    // For backwards-compatibility.
    force.distance = force.linkDistance;
  
    force.linkStrength = function(x) {
      if (!arguments.length) return linkStrength;
      linkStrength = d3.functor(x);
      return force;
    };
  
    force.friction = function(x) {
      if (!arguments.length) return friction;
      friction = x;
      return force;
    };
  
    force.charge = function(x) {
      if (!arguments.length) return charge;
      charge = typeof x === "function" ? x : +x;
      return force;
    };
  
    force.gravity = function(x) {
      if (!arguments.length) return gravity;
      gravity = x;
      return force;
    };
  
    force.theta = function(x) {
      if (!arguments.length) return theta;
      theta = x;
      return force;
    };
  
    force.alpha = function(x) {
      if (!arguments.length) return alpha;
  
      if (alpha) { // if we're already running
        if (x > 0) alpha = x; // we might keep it hot
        else alpha = 0; // or, next tick will dispatch "end"
      } else if (x > 0) { // otherwise, fire it up!
        event.start({type: "start", alpha: alpha = x});
        d3.timer(force.tick);
      }
  
      return force;
    };
  
    force.start = function() {
      var i,
          j,
          n = nodes.length,
          m = links.length,
          w = size[0],
          h = size[1],
          neighbors,
          o;
  
      for (i = 0; i < n; ++i) {
        (o = nodes[i]).index = i;
        o.weight = 0;
      }
  
      distances = [];
      strengths = [];
      for (i = 0; i < m; ++i) {
        o = links[i];
        if (typeof o.source == "number") o.source = nodes[o.source];
        if (typeof o.target == "number") o.target = nodes[o.target];
        distances[i] = linkDistance.call(this, o, i);
        strengths[i] = linkStrength.call(this, o, i);
        ++o.source.weight;
        ++o.target.weight;
      }
  
      for (i = 0; i < n; ++i) {
        o = nodes[i];
        if (isNaN(o.x)) o.x = position("x", w);
        if (isNaN(o.y)) o.y = position("y", h);
        if (isNaN(o.px)) o.px = o.x;
        if (isNaN(o.py)) o.py = o.y;
      }
  
      charges = [];
      if (typeof charge === "function") {
        for (i = 0; i < n; ++i) {
          charges[i] = +charge.call(this, nodes[i], i);
        }
      } else {
        for (i = 0; i < n; ++i) {
          charges[i] = charge;
        }
      }
  
      // initialize node position based on first neighbor
      function position(dimension, size) {
        var neighbors = neighbor(i),
            j = -1,
            m = neighbors.length,
            x;
        while (++j < m) if (!isNaN(x = neighbors[j][dimension])) return x;
        return Math.random() * size;
      }
  
      // initialize neighbors lazily
      function neighbor() {
        if (!neighbors) {
          neighbors = [];
          for (j = 0; j < n; ++j) {
            neighbors[j] = [];
          }
          for (j = 0; j < m; ++j) {
            var o = links[j];
            neighbors[o.source.index].push(o.target);
            neighbors[o.target.index].push(o.source);
          }
        }
        return neighbors[i];
      }
  
      return force.resume();
    };
  
    force.resume = function() {
      return force.alpha(.1);
    };
  
    force.stop = function() {
      return force.alpha(0);
    };
  
    // use `node.call(force.drag)` to make nodes draggable
    force.drag = function() {
      if (!drag) drag = d3.behavior.drag()
          .origin(Object)
          .on("dragstart", dragstart)
          .on("drag", d3_layout_forceDrag)
          .on("dragend", d3_layout_forceDragEnd);
  
      this.on("mouseover.force", d3_layout_forceDragOver)
          .on("mouseout.force", d3_layout_forceDragOut)
          .call(drag);
    };
  
    function dragstart(d) {
      d3_layout_forceDragOver(d3_layout_forceDragNode = d);
      d3_layout_forceDragForce = force;
    }
  
    return d3.rebind(force, event, "on");
  };
  
  var d3_layout_forceDragForce,
      d3_layout_forceDragNode;
  
  function d3_layout_forceDragOver(d) {
    d.fixed |= 2;
  }
  
  function d3_layout_forceDragOut(d) {
    if (d !== d3_layout_forceDragNode) d.fixed &= 1;
  }
  
  function d3_layout_forceDragEnd() {
    d3_layout_forceDragNode.fixed &= 1;
    d3_layout_forceDragForce = d3_layout_forceDragNode = null;
  }
  
  function d3_layout_forceDrag() {
    d3_layout_forceDragNode.px = d3.event.x;
    d3_layout_forceDragNode.py = d3.event.y;
    d3_layout_forceDragForce.resume(); // restart annealing
  }
  
  function d3_layout_forceAccumulate(quad, alpha, charges) {
    var cx = 0,
        cy = 0;
    quad.charge = 0;
    if (!quad.leaf) {
      var nodes = quad.nodes,
          n = nodes.length,
          i = -1,
          c;
      while (++i < n) {
        c = nodes[i];
        if (c == null) continue;
        d3_layout_forceAccumulate(c, alpha, charges);
        quad.charge += c.charge;
        cx += c.charge * c.cx;
        cy += c.charge * c.cy;
      }
    }
    if (quad.point) {
      // jitter internal nodes that are coincident
      if (!quad.leaf) {
        quad.point.x += Math.random() - .5;
        quad.point.y += Math.random() - .5;
      }
      var k = alpha * charges[quad.point.index];
      quad.charge += quad.pointCharge = k;
      cx += k * quad.point.x;
      cy += k * quad.point.y;
    }
    quad.cx = cx / quad.charge;
    quad.cy = cy / quad.charge;
  }
  
  function d3_layout_forceLinkDistance(link) {
    return 20;
  }
  
  function d3_layout_forceLinkStrength(link) {
    return 1;
  }
  d3.layout.partition = function() {
    var hierarchy = d3.layout.hierarchy(),
        size = [1, 1]; // width, height
  
    function position(node, x, dx, dy) {
      var children = node.children;
      node.x = x;
      node.y = node.depth * dy;
      node.dx = dx;
      node.dy = dy;
      if (children && (n = children.length)) {
        var i = -1,
            n,
            c,
            d;
        dx = node.value ? dx / node.value : 0;
        while (++i < n) {
          position(c = children[i], x, d = c.value * dx, dy);
          x += d;
        }
      }
    }
  
    function depth(node) {
      var children = node.children,
          d = 0;
      if (children && (n = children.length)) {
        var i = -1,
            n;
        while (++i < n) d = Math.max(d, depth(children[i]));
      }
      return 1 + d;
    }
  
    function partition(d, i) {
      var nodes = hierarchy.call(this, d, i);
      position(nodes[0], 0, size[0], size[1] / depth(nodes[0]));
      return nodes;
    }
  
    partition.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return partition;
    };
  
    return d3_layout_hierarchyRebind(partition, hierarchy);
  };
  d3.layout.pie = function() {
    var value = Number,
        sort = d3_layout_pieSortByValue,
        startAngle = 0,
        endAngle = 2 * Math.PI;
  
    function pie(data, i) {
  
      // Compute the numeric values for each data element.
      var values = data.map(function(d, i) { return +value.call(pie, d, i); });
  
      // Compute the start angle.
      var a = +(typeof startAngle === "function"
          ? startAngle.apply(this, arguments)
          : startAngle);
  
      // Compute the angular scale factor: from value to radians.
      var k = ((typeof endAngle === "function"
          ? endAngle.apply(this, arguments)
          : endAngle) - startAngle)
          / d3.sum(values);
  
      // Optionally sort the data.
      var index = d3.range(data.length);
      if (sort != null) index.sort(sort === d3_layout_pieSortByValue
          ? function(i, j) { return values[j] - values[i]; }
          : function(i, j) { return sort(data[i], data[j]); });
  
      // Compute the arcs!
      // They are stored in the original data's order.
      var arcs = [];
      index.forEach(function(i) {
        arcs[i] = {
          data: data[i],
          value: d = values[i],
          startAngle: a,
          endAngle: a += d * k
        };
      });
      return arcs;
    }
  
    /**
     * Specifies the value function *x*, which returns a nonnegative numeric value
     * for each datum. The default value function is `Number`. The value function
     * is passed two arguments: the current datum and the current index.
     */
    pie.value = function(x) {
      if (!arguments.length) return value;
      value = x;
      return pie;
    };
  
    /**
     * Specifies a sort comparison operator *x*. The comparator is passed two data
     * elements from the data array, a and b; it returns a negative value if a is
     * less than b, a positive value if a is greater than b, and zero if a equals
     * b.
     */
    pie.sort = function(x) {
      if (!arguments.length) return sort;
      sort = x;
      return pie;
    };
  
    /**
     * Specifies the overall start angle of the pie chart. Defaults to 0. The
     * start angle can be specified either as a constant or as a function; in the
     * case of a function, it is evaluated once per array (as opposed to per
     * element).
     */
    pie.startAngle = function(x) {
      if (!arguments.length) return startAngle;
      startAngle = x;
      return pie;
    };
  
    /**
     * Specifies the overall end angle of the pie chart. Defaults to 2π. The
     * end angle can be specified either as a constant or as a function; in the
     * case of a function, it is evaluated once per array (as opposed to per
     * element).
     */
    pie.endAngle = function(x) {
      if (!arguments.length) return endAngle;
      endAngle = x;
      return pie;
    };
  
    return pie;
  };
  
  var d3_layout_pieSortByValue = {};
  // data is two-dimensional array of x,y; we populate y0
  d3.layout.stack = function() {
    var values = Object,
        order = d3_layout_stackOrderDefault,
        offset = d3_layout_stackOffsetZero,
        out = d3_layout_stackOut,
        x = d3_layout_stackX,
        y = d3_layout_stackY;
  
    function stack(data, index) {
  
      // Convert series to canonical two-dimensional representation.
      var series = data.map(function(d, i) {
        return values.call(stack, d, i);
      });
  
      // Convert each series to canonical [[x,y]] representation.
      var points = series.map(function(d, i) {
        return d.map(function(v, i) {
          return [x.call(stack, v, i), y.call(stack, v, i)];
        });
      });
  
      // Compute the order of series, and permute them.
      var orders = order.call(stack, points, index);
      series = d3.permute(series, orders);
      points = d3.permute(points, orders);
  
      // Compute the baseline…
      var offsets = offset.call(stack, points, index);
  
      // And propagate it to other series.
      var n = series.length,
          m = series[0].length,
          i,
          j,
          o;
      for (j = 0; j < m; ++j) {
        out.call(stack, series[0][j], o = offsets[j], points[0][j][1]);
        for (i = 1; i < n; ++i) {
          out.call(stack, series[i][j], o += points[i - 1][j][1], points[i][j][1]);
        }
      }
  
      return data;
    }
  
    stack.values = function(x) {
      if (!arguments.length) return values;
      values = x;
      return stack;
    };
  
    stack.order = function(x) {
      if (!arguments.length) return order;
      order = typeof x === "function" ? x : d3_layout_stackOrders.get(x) || d3_layout_stackOrderDefault;
      return stack;
    };
  
    stack.offset = function(x) {
      if (!arguments.length) return offset;
      offset = typeof x === "function" ? x : d3_layout_stackOffsets.get(x) || d3_layout_stackOffsetZero;
      return stack;
    };
  
    stack.x = function(z) {
      if (!arguments.length) return x;
      x = z;
      return stack;
    };
  
    stack.y = function(z) {
      if (!arguments.length) return y;
      y = z;
      return stack;
    };
  
    stack.out = function(z) {
      if (!arguments.length) return out;
      out = z;
      return stack;
    };
  
    return stack;
  }
  
  function d3_layout_stackX(d) {
    return d.x;
  }
  
  function d3_layout_stackY(d) {
    return d.y;
  }
  
  function d3_layout_stackOut(d, y0, y) {
    d.y0 = y0;
    d.y = y;
  }
  
  var d3_layout_stackOrders = d3.map({
  
    "inside-out": function(data) {
      var n = data.length,
          i,
          j,
          max = data.map(d3_layout_stackMaxIndex),
          sums = data.map(d3_layout_stackReduceSum),
          index = d3.range(n).sort(function(a, b) { return max[a] - max[b]; }),
          top = 0,
          bottom = 0,
          tops = [],
          bottoms = [];
      for (i = 0; i < n; ++i) {
        j = index[i];
        if (top < bottom) {
          top += sums[j];
          tops.push(j);
        } else {
          bottom += sums[j];
          bottoms.push(j);
        }
      }
      return bottoms.reverse().concat(tops);
    },
  
    "reverse": function(data) {
      return d3.range(data.length).reverse();
    },
  
    "default": d3_layout_stackOrderDefault
  
  });
  
  var d3_layout_stackOffsets = d3.map({
  
    "silhouette": function(data) {
      var n = data.length,
          m = data[0].length,
          sums = [],
          max = 0,
          i,
          j,
          o,
          y0 = [];
      for (j = 0; j < m; ++j) {
        for (i = 0, o = 0; i < n; i++) o += data[i][j][1];
        if (o > max) max = o;
        sums.push(o);
      }
      for (j = 0; j < m; ++j) {
        y0[j] = (max - sums[j]) / 2;
      }
      return y0;
    },
  
    "wiggle": function(data) {
      var n = data.length,
          x = data[0],
          m = x.length,
          max = 0,
          i,
          j,
          k,
          s1,
          s2,
          s3,
          dx,
          o,
          o0,
          y0 = [];
      y0[0] = o = o0 = 0;
      for (j = 1; j < m; ++j) {
        for (i = 0, s1 = 0; i < n; ++i) s1 += data[i][j][1];
        for (i = 0, s2 = 0, dx = x[j][0] - x[j - 1][0]; i < n; ++i) {
          for (k = 0, s3 = (data[i][j][1] - data[i][j - 1][1]) / (2 * dx); k < i; ++k) {
            s3 += (data[k][j][1] - data[k][j - 1][1]) / dx;
          }
          s2 += s3 * data[i][j][1];
        }
        y0[j] = o -= s1 ? s2 / s1 * dx : 0;
        if (o < o0) o0 = o;
      }
      for (j = 0; j < m; ++j) y0[j] -= o0;
      return y0;
    },
  
    "expand": function(data) {
      var n = data.length,
          m = data[0].length,
          k = 1 / n,
          i,
          j,
          o,
          y0 = [];
      for (j = 0; j < m; ++j) {
        for (i = 0, o = 0; i < n; i++) o += data[i][j][1];
        if (o) for (i = 0; i < n; i++) data[i][j][1] /= o;
        else for (i = 0; i < n; i++) data[i][j][1] = k;
      }
      for (j = 0; j < m; ++j) y0[j] = 0;
      return y0;
    },
  
    "zero": d3_layout_stackOffsetZero
  
  });
  
  function d3_layout_stackOrderDefault(data) {
    return d3.range(data.length);
  }
  
  function d3_layout_stackOffsetZero(data) {
    var j = -1,
        m = data[0].length,
        y0 = [];
    while (++j < m) y0[j] = 0;
    return y0;
  }
  
  function d3_layout_stackMaxIndex(array) {
    var i = 1,
        j = 0,
        v = array[0][1],
        k,
        n = array.length;
    for (; i < n; ++i) {
      if ((k = array[i][1]) > v) {
        j = i;
        v = k;
      }
    }
    return j;
  }
  
  function d3_layout_stackReduceSum(d) {
    return d.reduce(d3_layout_stackSum, 0);
  }
  
  function d3_layout_stackSum(p, d) {
    return p + d[1];
  }
  d3.layout.histogram = function() {
    var frequency = true,
        valuer = Number,
        ranger = d3_layout_histogramRange,
        binner = d3_layout_histogramBinSturges;
  
    function histogram(data, i) {
      var bins = [],
          values = data.map(valuer, this),
          range = ranger.call(this, values, i),
          thresholds = binner.call(this, range, values, i),
          bin,
          i = -1,
          n = values.length,
          m = thresholds.length - 1,
          k = frequency ? 1 : 1 / n,
          x;
  
      // Initialize the bins.
      while (++i < m) {
        bin = bins[i] = [];
        bin.dx = thresholds[i + 1] - (bin.x = thresholds[i]);
        bin.y = 0;
      }
  
      // Fill the bins, ignoring values outside the range.
      i = -1; while(++i < n) {
        x = values[i];
        if ((x >= range[0]) && (x <= range[1])) {
          bin = bins[d3.bisect(thresholds, x, 1, m) - 1];
          bin.y += k;
          bin.push(data[i]);
        }
      }
  
      return bins;
    }
  
    // Specifies how to extract a value from the associated data. The default
    // value function is `Number`, which is equivalent to the identity function.
    histogram.value = function(x) {
      if (!arguments.length) return valuer;
      valuer = x;
      return histogram;
    };
  
    // Specifies the range of the histogram. Values outside the specified range
    // will be ignored. The argument `x` may be specified either as a two-element
    // array representing the minimum and maximum value of the range, or as a
    // function that returns the range given the array of values and the current
    // index `i`. The default range is the extent (minimum and maximum) of the
    // values.
    histogram.range = function(x) {
      if (!arguments.length) return ranger;
      ranger = d3.functor(x);
      return histogram;
    };
  
    // Specifies how to bin values in the histogram. The argument `x` may be
    // specified as a number, in which case the range of values will be split
    // uniformly into the given number of bins. Or, `x` may be an array of
    // threshold values, defining the bins; the specified array must contain the
    // rightmost (upper) value, thus specifying n + 1 values for n bins. Or, `x`
    // may be a function which is evaluated, being passed the range, the array of
    // values, and the current index `i`, returning an array of thresholds. The
    // default bin function will divide the values into uniform bins using
    // Sturges' formula.
    histogram.bins = function(x) {
      if (!arguments.length) return binner;
      binner = typeof x === "number"
          ? function(range) { return d3_layout_histogramBinFixed(range, x); }
          : d3.functor(x);
      return histogram;
    };
  
    // Specifies whether the histogram's `y` value is a count (frequency) or a
    // probability (density). The default value is true.
    histogram.frequency = function(x) {
      if (!arguments.length) return frequency;
      frequency = !!x;
      return histogram;
    };
  
    return histogram;
  };
  
  function d3_layout_histogramBinSturges(range, values) {
    return d3_layout_histogramBinFixed(range, Math.ceil(Math.log(values.length) / Math.LN2 + 1));
  }
  
  function d3_layout_histogramBinFixed(range, n) {
    var x = -1,
        b = +range[0],
        m = (range[1] - b) / n,
        f = [];
    while (++x <= n) f[x] = m * x + b;
    return f;
  }
  
  function d3_layout_histogramRange(values) {
    return [d3.min(values), d3.max(values)];
  }
  d3.layout.hierarchy = function() {
    var sort = d3_layout_hierarchySort,
        children = d3_layout_hierarchyChildren,
        value = d3_layout_hierarchyValue;
  
    // Recursively compute the node depth and value.
    // Also converts the data representation into a standard hierarchy structure.
    function recurse(data, depth, nodes) {
      var childs = children.call(hierarchy, data, depth),
          node = d3_layout_hierarchyInline ? data : {data: data};
      node.depth = depth;
      nodes.push(node);
      if (childs && (n = childs.length)) {
        var i = -1,
            n,
            c = node.children = [],
            v = 0,
            j = depth + 1;
        while (++i < n) {
          d = recurse(childs[i], j, nodes);
          d.parent = node;
          c.push(d);
          v += d.value;
        }
        if (sort) c.sort(sort);
        if (value) node.value = v;
      } else if (value) {
        node.value = +value.call(hierarchy, data, depth) || 0;
      }
      return node;
    }
  
    // Recursively re-evaluates the node value.
    function revalue(node, depth) {
      var children = node.children,
          v = 0;
      if (children && (n = children.length)) {
        var i = -1,
            n,
            j = depth + 1;
        while (++i < n) v += revalue(children[i], j);
      } else if (value) {
        v = +value.call(hierarchy, d3_layout_hierarchyInline ? node : node.data, depth) || 0;
      }
      if (value) node.value = v;
      return v;
    }
  
    function hierarchy(d) {
      var nodes = [];
      recurse(d, 0, nodes);
      return nodes;
    }
  
    hierarchy.sort = function(x) {
      if (!arguments.length) return sort;
      sort = x;
      return hierarchy;
    };
  
    hierarchy.children = function(x) {
      if (!arguments.length) return children;
      children = x;
      return hierarchy;
    };
  
    hierarchy.value = function(x) {
      if (!arguments.length) return value;
      value = x;
      return hierarchy;
    };
  
    // Re-evaluates the `value` property for the specified hierarchy.
    hierarchy.revalue = function(root) {
      revalue(root, 0);
      return root;
    };
  
    return hierarchy;
  };
  
  // A method assignment helper for hierarchy subclasses.
  function d3_layout_hierarchyRebind(object, hierarchy) {
    d3.rebind(object, hierarchy, "sort", "children", "value");
  
    // Add an alias for links, for convenience.
    object.links = d3_layout_hierarchyLinks;
  
    // If the new API is used, enabling inlining.
    object.nodes = function(d) {
      d3_layout_hierarchyInline = true;
      return (object.nodes = object)(d);
    };
  
    return object;
  }
  
  function d3_layout_hierarchyChildren(d) {
    return d.children;
  }
  
  function d3_layout_hierarchyValue(d) {
    return d.value;
  }
  
  function d3_layout_hierarchySort(a, b) {
    return b.value - a.value;
  }
  
  // Returns an array source+target objects for the specified nodes.
  function d3_layout_hierarchyLinks(nodes) {
    return d3.merge(nodes.map(function(parent) {
      return (parent.children || []).map(function(child) {
        return {source: parent, target: child};
      });
    }));
  }
  
  // For backwards-compatibility, don't enable inlining by default.
  var d3_layout_hierarchyInline = false;
  d3.layout.pack = function() {
    var hierarchy = d3.layout.hierarchy().sort(d3_layout_packSort),
        size = [1, 1];
  
    function pack(d, i) {
      var nodes = hierarchy.call(this, d, i),
          root = nodes[0];
  
      // Recursively compute the layout.
      root.x = 0;
      root.y = 0;
      d3_layout_packTree(root);
  
      // Scale the layout to fit the requested size.
      var w = size[0],
          h = size[1],
          k = 1 / Math.max(2 * root.r / w, 2 * root.r / h);
      d3_layout_packTransform(root, w / 2, h / 2, k);
  
      return nodes;
    }
  
    pack.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return pack;
    };
  
    return d3_layout_hierarchyRebind(pack, hierarchy);
  };
  
  function d3_layout_packSort(a, b) {
    return a.value - b.value;
  }
  
  function d3_layout_packInsert(a, b) {
    var c = a._pack_next;
    a._pack_next = b;
    b._pack_prev = a;
    b._pack_next = c;
    c._pack_prev = b;
  }
  
  function d3_layout_packSplice(a, b) {
    a._pack_next = b;
    b._pack_prev = a;
  }
  
  function d3_layout_packIntersects(a, b) {
    var dx = b.x - a.x,
        dy = b.y - a.y,
        dr = a.r + b.r;
    return dr * dr - dx * dx - dy * dy > .001; // within epsilon
  }
  
  function d3_layout_packCircle(nodes) {
    var xMin = Infinity,
        xMax = -Infinity,
        yMin = Infinity,
        yMax = -Infinity,
        n = nodes.length,
        a, b, c, j, k;
  
    function bound(node) {
      xMin = Math.min(node.x - node.r, xMin);
      xMax = Math.max(node.x + node.r, xMax);
      yMin = Math.min(node.y - node.r, yMin);
      yMax = Math.max(node.y + node.r, yMax);
    }
  
    // Create node links.
    nodes.forEach(d3_layout_packLink);
  
    // Create first node.
    a = nodes[0];
    a.x = -a.r;
    a.y = 0;
    bound(a);
  
    // Create second node.
    if (n > 1) {
      b = nodes[1];
      b.x = b.r;
      b.y = 0;
      bound(b);
  
      // Create third node and build chain.
      if (n > 2) {
        c = nodes[2];
        d3_layout_packPlace(a, b, c);
        bound(c);
        d3_layout_packInsert(a, c);
        a._pack_prev = c;
        d3_layout_packInsert(c, b);
        b = a._pack_next;
  
        // Now iterate through the rest.
        for (var i = 3; i < n; i++) {
          d3_layout_packPlace(a, b, c = nodes[i]);
  
          // Search for the closest intersection.
          var isect = 0, s1 = 1, s2 = 1;
          for (j = b._pack_next; j !== b; j = j._pack_next, s1++) {
            if (d3_layout_packIntersects(j, c)) {
              isect = 1;
              break;
            }
          }
          if (isect == 1) {
            for (k = a._pack_prev; k !== j._pack_prev; k = k._pack_prev, s2++) {
              if (d3_layout_packIntersects(k, c)) {
                break;
              }
            }
          }
  
          // Update node chain.
          if (isect) {
            if (s1 < s2 || (s1 == s2 && b.r < a.r)) d3_layout_packSplice(a, b = j);
            else d3_layout_packSplice(a = k, b);
            i--;
          } else {
            d3_layout_packInsert(a, c);
            b = c;
            bound(c);
          }
        }
      }
    }
  
    // Re-center the circles and return the encompassing radius.
    var cx = (xMin + xMax) / 2,
        cy = (yMin + yMax) / 2,
        cr = 0;
    for (var i = 0; i < n; i++) {
      var node = nodes[i];
      node.x -= cx;
      node.y -= cy;
      cr = Math.max(cr, node.r + Math.sqrt(node.x * node.x + node.y * node.y));
    }
  
    // Remove node links.
    nodes.forEach(d3_layout_packUnlink);
  
    return cr;
  }
  
  function d3_layout_packLink(node) {
    node._pack_next = node._pack_prev = node;
  }
  
  function d3_layout_packUnlink(node) {
    delete node._pack_next;
    delete node._pack_prev;
  }
  
  function d3_layout_packTree(node) {
    var children = node.children;
    if (children && children.length) {
      children.forEach(d3_layout_packTree);
      node.r = d3_layout_packCircle(children);
    } else {
      node.r = Math.sqrt(node.value);
    }
  }
  
  function d3_layout_packTransform(node, x, y, k) {
    var children = node.children;
    node.x = (x += k * node.x);
    node.y = (y += k * node.y);
    node.r *= k;
    if (children) {
      var i = -1, n = children.length;
      while (++i < n) d3_layout_packTransform(children[i], x, y, k);
    }
  }
  
  function d3_layout_packPlace(a, b, c) {
    var db = a.r + c.r,
        dx = b.x - a.x,
        dy = b.y - a.y;
    if (db && (dx || dy)) {
      var da = b.r + c.r,
          dc = Math.sqrt(dx * dx + dy * dy),
          cos = Math.max(-1, Math.min(1, (db * db + dc * dc - da * da) / (2 * db * dc))),
          theta = Math.acos(cos),
          x = cos * (db /= dc),
          y = Math.sin(theta) * db;
      c.x = a.x + x * dx + y * dy;
      c.y = a.y + x * dy - y * dx;
    } else {
      c.x = a.x + db;
      c.y = a.y;
    }
  }
  // Implements a hierarchical layout using the cluster (or dendrogram)
  // algorithm.
  d3.layout.cluster = function() {
    var hierarchy = d3.layout.hierarchy().sort(null).value(null),
        separation = d3_layout_treeSeparation,
        size = [1, 1]; // width, height
  
    function cluster(d, i) {
      var nodes = hierarchy.call(this, d, i),
          root = nodes[0],
          previousNode,
          x = 0,
          kx,
          ky;
  
      // First walk, computing the initial x & y values.
      d3_layout_treeVisitAfter(root, function(node) {
        var children = node.children;
        if (children && children.length) {
          node.x = d3_layout_clusterX(children);
          node.y = d3_layout_clusterY(children);
        } else {
          node.x = previousNode ? x += separation(node, previousNode) : 0;
          node.y = 0;
          previousNode = node;
        }
      });
  
      // Compute the left-most, right-most, and depth-most nodes for extents.
      var left = d3_layout_clusterLeft(root),
          right = d3_layout_clusterRight(root),
          x0 = left.x - separation(left, right) / 2,
          x1 = right.x + separation(right, left) / 2;
  
      // Second walk, normalizing x & y to the desired size.
      d3_layout_treeVisitAfter(root, function(node) {
        node.x = (node.x - x0) / (x1 - x0) * size[0];
        node.y = (1 - (root.y ? node.y / root.y : 1)) * size[1];
      });
  
      return nodes;
    }
  
    cluster.separation = function(x) {
      if (!arguments.length) return separation;
      separation = x;
      return cluster;
    };
  
    cluster.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return cluster;
    };
  
    return d3_layout_hierarchyRebind(cluster, hierarchy);
  };
  
  function d3_layout_clusterY(children) {
    return 1 + d3.max(children, function(child) {
      return child.y;
    });
  }
  
  function d3_layout_clusterX(children) {
    return children.reduce(function(x, child) {
      return x + child.x;
    }, 0) / children.length;
  }
  
  function d3_layout_clusterLeft(node) {
    var children = node.children;
    return children && children.length ? d3_layout_clusterLeft(children[0]) : node;
  }
  
  function d3_layout_clusterRight(node) {
    var children = node.children, n;
    return children && (n = children.length) ? d3_layout_clusterRight(children[n - 1]) : node;
  }
  // Node-link tree diagram using the Reingold-Tilford "tidy" algorithm
  d3.layout.tree = function() {
    var hierarchy = d3.layout.hierarchy().sort(null).value(null),
        separation = d3_layout_treeSeparation,
        size = [1, 1]; // width, height
  
    function tree(d, i) {
      var nodes = hierarchy.call(this, d, i),
          root = nodes[0];
  
      function firstWalk(node, previousSibling) {
        var children = node.children,
            layout = node._tree;
        if (children && (n = children.length)) {
          var n,
              firstChild = children[0],
              previousChild,
              ancestor = firstChild,
              child,
              i = -1;
          while (++i < n) {
            child = children[i];
            firstWalk(child, previousChild);
            ancestor = apportion(child, previousChild, ancestor);
            previousChild = child;
          }
          d3_layout_treeShift(node);
          var midpoint = .5 * (firstChild._tree.prelim + child._tree.prelim);
          if (previousSibling) {
            layout.prelim = previousSibling._tree.prelim + separation(node, previousSibling);
            layout.mod = layout.prelim - midpoint;
          } else {
            layout.prelim = midpoint;
          }
        } else {
          if (previousSibling) {
            layout.prelim = previousSibling._tree.prelim + separation(node, previousSibling);
          }
        }
      }
  
      function secondWalk(node, x) {
        node.x = node._tree.prelim + x;
        var children = node.children;
        if (children && (n = children.length)) {
          var i = -1,
              n;
          x += node._tree.mod;
          while (++i < n) {
            secondWalk(children[i], x);
          }
        }
      }
  
      function apportion(node, previousSibling, ancestor) {
        if (previousSibling) {
          var vip = node,
              vop = node,
              vim = previousSibling,
              vom = node.parent.children[0],
              sip = vip._tree.mod,
              sop = vop._tree.mod,
              sim = vim._tree.mod,
              som = vom._tree.mod,
              shift;
          while (vim = d3_layout_treeRight(vim), vip = d3_layout_treeLeft(vip), vim && vip) {
            vom = d3_layout_treeLeft(vom);
            vop = d3_layout_treeRight(vop);
            vop._tree.ancestor = node;
            shift = vim._tree.prelim + sim - vip._tree.prelim - sip + separation(vim, vip);
            if (shift > 0) {
              d3_layout_treeMove(d3_layout_treeAncestor(vim, node, ancestor), node, shift);
              sip += shift;
              sop += shift;
            }
            sim += vim._tree.mod;
            sip += vip._tree.mod;
            som += vom._tree.mod;
            sop += vop._tree.mod;
          }
          if (vim && !d3_layout_treeRight(vop)) {
            vop._tree.thread = vim;
            vop._tree.mod += sim - sop;
          }
          if (vip && !d3_layout_treeLeft(vom)) {
            vom._tree.thread = vip;
            vom._tree.mod += sip - som;
            ancestor = node;
          }
        }
        return ancestor;
      }
  
      // Initialize temporary layout variables.
      d3_layout_treeVisitAfter(root, function(node, previousSibling) {
        node._tree = {
          ancestor: node,
          prelim: 0,
          mod: 0,
          change: 0,
          shift: 0,
          number: previousSibling ? previousSibling._tree.number + 1 : 0
        };
      });
  
      // Compute the layout using Buchheim et al.'s algorithm.
      firstWalk(root);
      secondWalk(root, -root._tree.prelim);
  
      // Compute the left-most, right-most, and depth-most nodes for extents.
      var left = d3_layout_treeSearch(root, d3_layout_treeLeftmost),
          right = d3_layout_treeSearch(root, d3_layout_treeRightmost),
          deep = d3_layout_treeSearch(root, d3_layout_treeDeepest),
          x0 = left.x - separation(left, right) / 2,
          x1 = right.x + separation(right, left) / 2,
          y1 = deep.depth || 1;
  
      // Clear temporary layout variables; transform x and y.
      d3_layout_treeVisitAfter(root, function(node) {
        node.x = (node.x - x0) / (x1 - x0) * size[0];
        node.y = node.depth / y1 * size[1];
        delete node._tree;
      });
  
      return nodes;
    }
  
    tree.separation = function(x) {
      if (!arguments.length) return separation;
      separation = x;
      return tree;
    };
  
    tree.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return tree;
    };
  
    return d3_layout_hierarchyRebind(tree, hierarchy);
  };
  
  function d3_layout_treeSeparation(a, b) {
    return a.parent == b.parent ? 1 : 2;
  }
  
  // function d3_layout_treeSeparationRadial(a, b) {
  //   return (a.parent == b.parent ? 1 : 2) / a.depth;
  // }
  
  function d3_layout_treeLeft(node) {
    var children = node.children;
    return children && children.length ? children[0] : node._tree.thread;
  }
  
  function d3_layout_treeRight(node) {
    var children = node.children,
        n;
    return children && (n = children.length) ? children[n - 1] : node._tree.thread;
  }
  
  function d3_layout_treeSearch(node, compare) {
    var children = node.children;
    if (children && (n = children.length)) {
      var child,
          n,
          i = -1;
      while (++i < n) {
        if (compare(child = d3_layout_treeSearch(children[i], compare), node) > 0) {
          node = child;
        }
      }
    }
    return node;
  }
  
  function d3_layout_treeRightmost(a, b) {
    return a.x - b.x;
  }
  
  function d3_layout_treeLeftmost(a, b) {
    return b.x - a.x;
  }
  
  function d3_layout_treeDeepest(a, b) {
    return a.depth - b.depth;
  }
  
  function d3_layout_treeVisitAfter(node, callback) {
    function visit(node, previousSibling) {
      var children = node.children;
      if (children && (n = children.length)) {
        var child,
            previousChild = null,
            i = -1,
            n;
        while (++i < n) {
          child = children[i];
          visit(child, previousChild);
          previousChild = child;
        }
      }
      callback(node, previousSibling);
    }
    visit(node, null);
  }
  
  function d3_layout_treeShift(node) {
    var shift = 0,
        change = 0,
        children = node.children,
        i = children.length,
        child;
    while (--i >= 0) {
      child = children[i]._tree;
      child.prelim += shift;
      child.mod += shift;
      shift += child.shift + (change += child.change);
    }
  }
  
  function d3_layout_treeMove(ancestor, node, shift) {
    ancestor = ancestor._tree;
    node = node._tree;
    var change = shift / (node.number - ancestor.number);
    ancestor.change += change;
    node.change -= change;
    node.shift += shift;
    node.prelim += shift;
    node.mod += shift;
  }
  
  function d3_layout_treeAncestor(vim, node, ancestor) {
    return vim._tree.ancestor.parent == node.parent
        ? vim._tree.ancestor
        : ancestor;
  }
  // Squarified Treemaps by Mark Bruls, Kees Huizing, and Jarke J. van Wijk
  // Modified to support a target aspect ratio by Jeff Heer
  d3.layout.treemap = function() {
    var hierarchy = d3.layout.hierarchy(),
        round = Math.round,
        size = [1, 1], // width, height
        padding = null,
        pad = d3_layout_treemapPadNull,
        sticky = false,
        stickies,
        ratio = 0.5 * (1 + Math.sqrt(5)); // golden ratio
  
    // Compute the area for each child based on value & scale.
    function scale(children, k) {
      var i = -1,
          n = children.length,
          child,
          area;
      while (++i < n) {
        area = (child = children[i]).value * (k < 0 ? 0 : k);
        child.area = isNaN(area) || area <= 0 ? 0 : area;
      }
    }
  
    // Recursively arranges the specified node's children into squarified rows.
    function squarify(node) {
      var children = node.children;
      if (children && children.length) {
        var rect = pad(node),
            row = [],
            remaining = children.slice(), // copy-on-write
            child,
            best = Infinity, // the best row score so far
            score, // the current row score
            u = Math.min(rect.dx, rect.dy), // initial orientation
            n;
        scale(remaining, rect.dx * rect.dy / node.value);
        row.area = 0;
        while ((n = remaining.length) > 0) {
          row.push(child = remaining[n - 1]);
          row.area += child.area;
          if ((score = worst(row, u)) <= best) { // continue with this orientation
            remaining.pop();
            best = score;
          } else { // abort, and try a different orientation
            row.area -= row.pop().area;
            position(row, u, rect, false);
            u = Math.min(rect.dx, rect.dy);
            row.length = row.area = 0;
            best = Infinity;
          }
        }
        if (row.length) {
          position(row, u, rect, true);
          row.length = row.area = 0;
        }
        children.forEach(squarify);
      }
    }
  
    // Recursively resizes the specified node's children into existing rows.
    // Preserves the existing layout!
    function stickify(node) {
      var children = node.children;
      if (children && children.length) {
        var rect = pad(node),
            remaining = children.slice(), // copy-on-write
            child,
            row = [];
        scale(remaining, rect.dx * rect.dy / node.value);
        row.area = 0;
        while (child = remaining.pop()) {
          row.push(child);
          row.area += child.area;
          if (child.z != null) {
            position(row, child.z ? rect.dx : rect.dy, rect, !remaining.length);
            row.length = row.area = 0;
          }
        }
        children.forEach(stickify);
      }
    }
  
    // Computes the score for the specified row, as the worst aspect ratio.
    function worst(row, u) {
      var s = row.area,
          r,
          rmax = 0,
          rmin = Infinity,
          i = -1,
          n = row.length;
      while (++i < n) {
        if (!(r = row[i].area)) continue;
        if (r < rmin) rmin = r;
        if (r > rmax) rmax = r;
      }
      s *= s;
      u *= u;
      return s
          ? Math.max((u * rmax * ratio) / s, s / (u * rmin * ratio))
          : Infinity;
    }
  
    // Positions the specified row of nodes. Modifies `rect`.
    function position(row, u, rect, flush) {
      var i = -1,
          n = row.length,
          x = rect.x,
          y = rect.y,
          v = u ? round(row.area / u) : 0,
          o;
      if (u == rect.dx) { // horizontal subdivision
        if (flush || v > rect.dy) v = rect.dy; // over+underflow
        while (++i < n) {
          o = row[i];
          o.x = x;
          o.y = y;
          o.dy = v;
          x += o.dx = Math.min(rect.x + rect.dx - x, v ? round(o.area / v) : 0);
        }
        o.z = true;
        o.dx += rect.x + rect.dx - x; // rounding error
        rect.y += v;
        rect.dy -= v;
      } else { // vertical subdivision
        if (flush || v > rect.dx) v = rect.dx; // over+underflow
        while (++i < n) {
          o = row[i];
          o.x = x;
          o.y = y;
          o.dx = v;
          y += o.dy = Math.min(rect.y + rect.dy - y, v ? round(o.area / v) : 0);
        }
        o.z = false;
        o.dy += rect.y + rect.dy - y; // rounding error
        rect.x += v;
        rect.dx -= v;
      }
    }
  
    function treemap(d) {
      var nodes = stickies || hierarchy(d),
          root = nodes[0];
      root.x = 0;
      root.y = 0;
      root.dx = size[0];
      root.dy = size[1];
      if (stickies) hierarchy.revalue(root);
      scale([root], root.dx * root.dy / root.value);
      (stickies ? stickify : squarify)(root);
      if (sticky) stickies = nodes;
      return nodes;
    }
  
    treemap.size = function(x) {
      if (!arguments.length) return size;
      size = x;
      return treemap;
    };
  
    treemap.padding = function(x) {
      if (!arguments.length) return padding;
  
      function padFunction(node) {
        var p = x.call(treemap, node, node.depth);
        return p == null
            ? d3_layout_treemapPadNull(node)
            : d3_layout_treemapPad(node, typeof p === "number" ? [p, p, p, p] : p);
      }
  
      function padConstant(node) {
        return d3_layout_treemapPad(node, x);
      }
  
      var type;
      pad = (padding = x) == null ? d3_layout_treemapPadNull
          : (type = typeof x) === "function" ? padFunction
          : type === "number" ? (x = [x, x, x, x], padConstant)
          : padConstant;
      return treemap;
    };
  
    treemap.round = function(x) {
      if (!arguments.length) return round != Number;
      round = x ? Math.round : Number;
      return treemap;
    };
  
    treemap.sticky = function(x) {
      if (!arguments.length) return sticky;
      sticky = x;
      stickies = null;
      return treemap;
    };
  
    treemap.ratio = function(x) {
      if (!arguments.length) return ratio;
      ratio = x;
      return treemap;
    };
  
    return d3_layout_hierarchyRebind(treemap, hierarchy);
  };
  
  function d3_layout_treemapPadNull(node) {
    return {x: node.x, y: node.y, dx: node.dx, dy: node.dy};
  }
  
  function d3_layout_treemapPad(node, padding) {
    var x = node.x + padding[3],
        y = node.y + padding[0],
        dx = node.dx - padding[1] - padding[3],
        dy = node.dy - padding[0] - padding[2];
    if (dx < 0) { x += dx / 2; dx = 0; }
    if (dy < 0) { y += dy / 2; dy = 0; }
    return {x: x, y: y, dx: dx, dy: dy};
  }
  d3.csv = function(url, callback) {
    d3.text(url, "text/csv", function(text) {
      callback(text && d3.csv.parse(text));
    });
  };
  d3.csv.parse = function(text) {
    var header;
    return d3.csv.parseRows(text, function(row, i) {
      if (i) {
        var o = {}, j = -1, m = header.length;
        while (++j < m) o[header[j]] = row[j];
        return o;
      } else {
        header = row;
        return null;
      }
    });
  };
  
  d3.csv.parseRows = function(text, f) {
    var EOL = {}, // sentinel value for end-of-line
        EOF = {}, // sentinel value for end-of-file
        rows = [], // output rows
        re = /\r\n|[,\r\n]/g, // field separator regex
        n = 0, // the current line number
        t, // the current token
        eol; // is the current token followed by EOL?
  
    re.lastIndex = 0; // work-around bug in FF 3.6
  
    /** @private Returns the next token. */
    function token() {
      if (re.lastIndex >= text.length) return EOF; // special case: end of file
      if (eol) { eol = false; return EOL; } // special case: end of line
  
      // special case: quotes
      var j = re.lastIndex;
      if (text.charCodeAt(j) === 34) {
        var i = j;
        while (i++ < text.length) {
          if (text.charCodeAt(i) === 34) {
            if (text.charCodeAt(i + 1) !== 34) break;
            i++;
          }
        }
        re.lastIndex = i + 2;
        var c = text.charCodeAt(i + 1);
        if (c === 13) {
          eol = true;
          if (text.charCodeAt(i + 2) === 10) re.lastIndex++;
        } else if (c === 10) {
          eol = true;
        }
        return text.substring(j + 1, i).replace(/""/g, "\"");
      }
  
      // common case
      var m = re.exec(text);
      if (m) {
        eol = m[0].charCodeAt(0) !== 44;
        return text.substring(j, m.index);
      }
      re.lastIndex = text.length;
      return text.substring(j);
    }
  
    while ((t = token()) !== EOF) {
      var a = [];
      while ((t !== EOL) && (t !== EOF)) {
        a.push(t);
        t = token();
      }
      if (f && !(a = f(a, n++))) continue;
      rows.push(a);
    }
  
    return rows;
  };
  d3.csv.format = function(rows) {
    return rows.map(d3_csv_formatRow).join("\n");
  };
  
  function d3_csv_formatRow(row) {
    return row.map(d3_csv_formatValue).join(",");
  }
  
  function d3_csv_formatValue(text) {
    return /[",\n]/.test(text)
        ? "\"" + text.replace(/\"/g, "\"\"") + "\""
        : text;
  }
  d3.geo = {};
  
  var d3_geo_radians = Math.PI / 180;
  // TODO clip input coordinates on opposite hemisphere
  d3.geo.azimuthal = function() {
    var mode = "orthographic", // or stereographic, gnomonic, equidistant or equalarea
        origin,
        scale = 200,
        translate = [480, 250],
        x0,
        y0,
        cy0,
        sy0;
  
    function azimuthal(coordinates) {
      var x1 = coordinates[0] * d3_geo_radians - x0,
          y1 = coordinates[1] * d3_geo_radians,
          cx1 = Math.cos(x1),
          sx1 = Math.sin(x1),
          cy1 = Math.cos(y1),
          sy1 = Math.sin(y1),
          cc = mode !== "orthographic" ? sy0 * sy1 + cy0 * cy1 * cx1 : null,
          c,
          k = mode === "stereographic" ? 1 / (1 + cc)
            : mode === "gnomonic" ? 1 / cc
            : mode === "equidistant" ? (c = Math.acos(cc), c ? c / Math.sin(c) : 0)
            : mode === "equalarea" ? Math.sqrt(2 / (1 + cc))
            : 1,
          x = k * cy1 * sx1,
          y = k * (sy0 * cy1 * cx1 - cy0 * sy1);
      return [
        scale * x + translate[0],
        scale * y + translate[1]
      ];
    }
  
    azimuthal.invert = function(coordinates) {
      var x = (coordinates[0] - translate[0]) / scale,
          y = (coordinates[1] - translate[1]) / scale,
          p = Math.sqrt(x * x + y * y),
          c = mode === "stereographic" ? 2 * Math.atan(p)
            : mode === "gnomonic" ? Math.atan(p)
            : mode === "equidistant" ? p
            : mode === "equalarea" ? 2 * Math.asin(.5 * p)
            : Math.asin(p),
          sc = Math.sin(c),
          cc = Math.cos(c);
      return [
        (x0 + Math.atan2(x * sc, p * cy0 * cc + y * sy0 * sc)) / d3_geo_radians,
        Math.asin(cc * sy0 - (p ? (y * sc * cy0) / p : 0)) / d3_geo_radians
      ];
    };
  
    azimuthal.mode = function(x) {
      if (!arguments.length) return mode;
      mode = x + "";
      return azimuthal;
    };
  
    azimuthal.origin = function(x) {
      if (!arguments.length) return origin;
      origin = x;
      x0 = origin[0] * d3_geo_radians;
      y0 = origin[1] * d3_geo_radians;
      cy0 = Math.cos(y0);
      sy0 = Math.sin(y0);
      return azimuthal;
    };
  
    azimuthal.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return azimuthal;
    };
  
    azimuthal.translate = function(x) {
      if (!arguments.length) return translate;
      translate = [+x[0], +x[1]];
      return azimuthal;
    };
  
    return azimuthal.origin([0, 0]);
  };
  // Derived from Tom Carden's Albers implementation for Protovis.
  // http://gist.github.com/476238
  // http://mathworld.wolfram.com/AlbersEqual-AreaConicProjection.html
  
  d3.geo.albers = function() {
    var origin = [-98, 38],
        parallels = [29.5, 45.5],
        scale = 1000,
        translate = [480, 250],
        lng0, // d3_geo_radians * origin[0]
        n,
        C,
        p0;
  
    function albers(coordinates) {
      var t = n * (d3_geo_radians * coordinates[0] - lng0),
          p = Math.sqrt(C - 2 * n * Math.sin(d3_geo_radians * coordinates[1])) / n;
      return [
        scale * p * Math.sin(t) + translate[0],
        scale * (p * Math.cos(t) - p0) + translate[1]
      ];
    }
  
    albers.invert = function(coordinates) {
      var x = (coordinates[0] - translate[0]) / scale,
          y = (coordinates[1] - translate[1]) / scale,
          p0y = p0 + y,
          t = Math.atan2(x, p0y),
          p = Math.sqrt(x * x + p0y * p0y);
      return [
        (lng0 + t / n) / d3_geo_radians,
        Math.asin((C - p * p * n * n) / (2 * n)) / d3_geo_radians
      ];
    };
  
    function reload() {
      var phi1 = d3_geo_radians * parallels[0],
          phi2 = d3_geo_radians * parallels[1],
          lat0 = d3_geo_radians * origin[1],
          s = Math.sin(phi1),
          c = Math.cos(phi1);
      lng0 = d3_geo_radians * origin[0];
      n = .5 * (s + Math.sin(phi2));
      C = c * c + 2 * n * s;
      p0 = Math.sqrt(C - 2 * n * Math.sin(lat0)) / n;
      return albers;
    }
  
    albers.origin = function(x) {
      if (!arguments.length) return origin;
      origin = [+x[0], +x[1]];
      return reload();
    };
  
    albers.parallels = function(x) {
      if (!arguments.length) return parallels;
      parallels = [+x[0], +x[1]];
      return reload();
    };
  
    albers.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return albers;
    };
  
    albers.translate = function(x) {
      if (!arguments.length) return translate;
      translate = [+x[0], +x[1]];
      return albers;
    };
  
    return reload();
  };
  
  // A composite projection for the United States, 960x500. The set of standard
  // parallels for each region comes from USGS, which is published here:
  // http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html#albers
  // TODO allow the composite projection to be rescaled?
  d3.geo.albersUsa = function() {
    var lower48 = d3.geo.albers();
  
    var alaska = d3.geo.albers()
        .origin([-160, 60])
        .parallels([55, 65]);
  
    var hawaii = d3.geo.albers()
        .origin([-160, 20])
        .parallels([8, 18]);
  
    var puertoRico = d3.geo.albers()
        .origin([-60, 10])
        .parallels([8, 18]);
  
    function albersUsa(coordinates) {
      var lon = coordinates[0],
          lat = coordinates[1];
      return (lat > 50 ? alaska
          : lon < -140 ? hawaii
          : lat < 21 ? puertoRico
          : lower48)(coordinates);
    }
  
    albersUsa.scale = function(x) {
      if (!arguments.length) return lower48.scale();
      lower48.scale(x);
      alaska.scale(x * .6);
      hawaii.scale(x);
      puertoRico.scale(x * 1.5);
      return albersUsa.translate(lower48.translate());
    };
  
    albersUsa.translate = function(x) {
      if (!arguments.length) return lower48.translate();
      var dz = lower48.scale() / 1000,
          dx = x[0],
          dy = x[1];
      lower48.translate(x);
      alaska.translate([dx - 400 * dz, dy + 170 * dz]);
      hawaii.translate([dx - 190 * dz, dy + 200 * dz]);
      puertoRico.translate([dx + 580 * dz, dy + 430 * dz]);
      return albersUsa;
    };
  
    return albersUsa.scale(lower48.scale());
  };
  d3.geo.bonne = function() {
    var scale = 200,
        translate = [480, 250],
        x0, // origin longitude in radians
        y0, // origin latitude in radians
        y1, // parallel latitude in radians
        c1; // cot(y1)
  
    function bonne(coordinates) {
      var x = coordinates[0] * d3_geo_radians - x0,
          y = coordinates[1] * d3_geo_radians - y0;
      if (y1) {
        var p = c1 + y1 - y, E = x * Math.cos(y) / p;
        x = p * Math.sin(E);
        y = p * Math.cos(E) - c1;
      } else {
        x *= Math.cos(y);
        y *= -1;
      }
      return [
        scale * x + translate[0],
        scale * y + translate[1]
      ];
    }
  
    bonne.invert = function(coordinates) {
      var x = (coordinates[0] - translate[0]) / scale,
          y = (coordinates[1] - translate[1]) / scale;
      if (y1) {
        var c = c1 + y, p = Math.sqrt(x * x + c * c);
        y = c1 + y1 - p;
        x = x0 + p * Math.atan2(x, c) / Math.cos(y);
      } else {
        y *= -1;
        x /= Math.cos(y);
      }
      return [
        x / d3_geo_radians,
        y / d3_geo_radians
      ];
    };
  
    // 90° for Werner, 0° for Sinusoidal
    bonne.parallel = function(x) {
      if (!arguments.length) return y1 / d3_geo_radians;
      c1 = 1 / Math.tan(y1 = x * d3_geo_radians);
      return bonne;
    };
  
    bonne.origin = function(x) {
      if (!arguments.length) return [x0 / d3_geo_radians, y0 / d3_geo_radians];
      x0 = x[0] * d3_geo_radians;
      y0 = x[1] * d3_geo_radians;
      return bonne;
    };
  
    bonne.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return bonne;
    };
  
    bonne.translate = function(x) {
      if (!arguments.length) return translate;
      translate = [+x[0], +x[1]];
      return bonne;
    };
  
    return bonne.origin([0, 0]).parallel(45);
  };
  d3.geo.equirectangular = function() {
    var scale = 500,
        translate = [480, 250];
  
    function equirectangular(coordinates) {
      var x = coordinates[0] / 360,
          y = -coordinates[1] / 360;
      return [
        scale * x + translate[0],
        scale * y + translate[1]
      ];
    }
  
    equirectangular.invert = function(coordinates) {
      var x = (coordinates[0] - translate[0]) / scale,
          y = (coordinates[1] - translate[1]) / scale;
      return [
        360 * x,
        -360 * y
      ];
    };
  
    equirectangular.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return equirectangular;
    };
  
    equirectangular.translate = function(x) {
      if (!arguments.length) return translate;
      translate = [+x[0], +x[1]];
      return equirectangular;
    };
  
    return equirectangular;
  };
  d3.geo.mercator = function() {
    var scale = 500,
        translate = [480, 250];
  
    function mercator(coordinates) {
      var x = coordinates[0] / 360,
          y = -(Math.log(Math.tan(Math.PI / 4 + coordinates[1] * d3_geo_radians / 2)) / d3_geo_radians) / 360;
      return [
        scale * x + translate[0],
        scale * Math.max(-.5, Math.min(.5, y)) + translate[1]
      ];
    }
  
    mercator.invert = function(coordinates) {
      var x = (coordinates[0] - translate[0]) / scale,
          y = (coordinates[1] - translate[1]) / scale;
      return [
        360 * x,
        2 * Math.atan(Math.exp(-360 * y * d3_geo_radians)) / d3_geo_radians - 90
      ];
    };
  
    mercator.scale = function(x) {
      if (!arguments.length) return scale;
      scale = +x;
      return mercator;
    };
  
    mercator.translate = function(x) {
      if (!arguments.length) return translate;
      translate = [+x[0], +x[1]];
      return mercator;
    };
  
    return mercator;
  };
  function d3_geo_type(types, defaultValue) {
    return function(object) {
      return object && types.hasOwnProperty(object.type) ? types[object.type](object) : defaultValue;
    };
  }
  /**
   * Returns a function that, given a GeoJSON object (e.g., a feature), returns
   * the corresponding SVG path. The function can be customized by overriding the
   * projection. Point features are mapped to circles with a default radius of
   * 4.5px; the radius can be specified either as a constant or a function that
   * is evaluated per object.
   */
  d3.geo.path = function() {
    var pointRadius = 4.5,
        pointCircle = d3_path_circle(pointRadius),
        projection = d3.geo.albersUsa();
  
    function path(d, i) {
      if (typeof pointRadius === "function") {
        pointCircle = d3_path_circle(pointRadius.apply(this, arguments));
      }
      return pathType(d) || null;
    }
  
    function project(coordinates) {
      return projection(coordinates).join(",");
    }
  
    var pathType = d3_geo_type({
  
      FeatureCollection: function(o) {
        var path = [],
            features = o.features,
            i = -1, // features.index
            n = features.length;
        while (++i < n) path.push(pathType(features[i].geometry));
        return path.join("");
      },
  
      Feature: function(o) {
        return pathType(o.geometry);
      },
  
      Point: function(o) {
        return "M" + project(o.coordinates) + pointCircle;
      },
  
      MultiPoint: function(o) {
        var path = [],
            coordinates = o.coordinates,
            i = -1, // coordinates.index
            n = coordinates.length;
        while (++i < n) path.push("M", project(coordinates[i]), pointCircle);
        return path.join("");
      },
  
      LineString: function(o) {
        var path = ["M"],
            coordinates = o.coordinates,
            i = -1, // coordinates.index
            n = coordinates.length;
        while (++i < n) path.push(project(coordinates[i]), "L");
        path.pop();
        return path.join("");
      },
  
      MultiLineString: function(o) {
        var path = [],
            coordinates = o.coordinates,
            i = -1, // coordinates.index
            n = coordinates.length,
            subcoordinates, // coordinates[i]
            j, // subcoordinates.index
            m; // subcoordinates.length
        while (++i < n) {
          subcoordinates = coordinates[i];
          j = -1;
          m = subcoordinates.length;
          path.push("M");
          while (++j < m) path.push(project(subcoordinates[j]), "L");
          path.pop();
        }
        return path.join("");
      },
  
      Polygon: function(o) {
        var path = [],
            coordinates = o.coordinates,
            i = -1, // coordinates.index
            n = coordinates.length,
            subcoordinates, // coordinates[i]
            j, // subcoordinates.index
            m; // subcoordinates.length
        while (++i < n) {
          subcoordinates = coordinates[i];
          j = -1;
          if ((m = subcoordinates.length - 1) > 0) {
            path.push("M");
            while (++j < m) path.push(project(subcoordinates[j]), "L");
            path[path.length - 1] = "Z";
          }
        }
        return path.join("");
      },
  
      MultiPolygon: function(o) {
        var path = [],
            coordinates = o.coordinates,
            i = -1, // coordinates index
            n = coordinates.length,
            subcoordinates, // coordinates[i]
            j, // subcoordinates index
            m, // subcoordinates.length
            subsubcoordinates, // subcoordinates[j]
            k, // subsubcoordinates index
            p; // subsubcoordinates.length
        while (++i < n) {
          subcoordinates = coordinates[i];
          j = -1;
          m = subcoordinates.length;
          while (++j < m) {
            subsubcoordinates = subcoordinates[j];
            k = -1;
            if ((p = subsubcoordinates.length - 1) > 0) {
              path.push("M");
              while (++k < p) path.push(project(subsubcoordinates[k]), "L");
              path[path.length - 1] = "Z";
            }
          }
        }
        return path.join("");
      },
  
      GeometryCollection: function(o) {
        var path = [],
            geometries = o.geometries,
            i = -1, // geometries index
            n = geometries.length;
        while (++i < n) path.push(pathType(geometries[i]));
        return path.join("");
      }
  
    });
  
    var areaType = path.area = d3_geo_type({
  
      FeatureCollection: function(o) {
        var area = 0,
            features = o.features,
            i = -1, // features.index
            n = features.length;
        while (++i < n) area += areaType(features[i]);
        return area;
      },
  
      Feature: function(o) {
        return areaType(o.geometry);
      },
  
      Polygon: function(o) {
        return polygonArea(o.coordinates);
      },
  
      MultiPolygon: function(o) {
        var sum = 0,
            coordinates = o.coordinates,
            i = -1, // coordinates index
            n = coordinates.length;
        while (++i < n) sum += polygonArea(coordinates[i]);
        return sum;
      },
  
      GeometryCollection: function(o) {
        var sum = 0,
            geometries = o.geometries,
            i = -1, // geometries index
            n = geometries.length;
        while (++i < n) sum += areaType(geometries[i]);
        return sum;
      }
  
    }, 0);
  
    function polygonArea(coordinates) {
      var sum = area(coordinates[0]), // exterior ring
          i = 0, // coordinates.index
          n = coordinates.length;
      while (++i < n) sum -= area(coordinates[i]); // holes
      return sum;
    }
  
    function polygonCentroid(coordinates) {
      var polygon = d3.geom.polygon(coordinates[0].map(projection)), // exterior ring
          area = polygon.area(),
          centroid = polygon.centroid(area < 0 ? (area *= -1, 1) : -1),
          x = centroid[0],
          y = centroid[1],
          z = area,
          i = 0, // coordinates index
          n = coordinates.length;
      while (++i < n) {
        polygon = d3.geom.polygon(coordinates[i].map(projection)); // holes
        area = polygon.area();
        centroid = polygon.centroid(area < 0 ? (area *= -1, 1) : -1);
        x -= centroid[0];
        y -= centroid[1];
        z -= area;
      }
      return [x, y, 6 * z]; // weighted centroid
    }
  
    var centroidType = path.centroid = d3_geo_type({
  
      // TODO FeatureCollection
      // TODO Point
      // TODO MultiPoint
      // TODO LineString
      // TODO MultiLineString
      // TODO GeometryCollection
  
      Feature: function(o) {
        return centroidType(o.geometry);
      },
  
      Polygon: function(o) {
        var centroid = polygonCentroid(o.coordinates);
        return [centroid[0] / centroid[2], centroid[1] / centroid[2]];
      },
  
      MultiPolygon: function(o) {
        var area = 0,
            coordinates = o.coordinates,
            centroid,
            x = 0,
            y = 0,
            z = 0,
            i = -1, // coordinates index
            n = coordinates.length;
        while (++i < n) {
          centroid = polygonCentroid(coordinates[i]);
          x += centroid[0];
          y += centroid[1];
          z += centroid[2];
        }
        return [x / z, y / z];
      }
  
    });
  
    function area(coordinates) {
      return Math.abs(d3.geom.polygon(coordinates.map(projection)).area());
    }
  
    path.projection = function(x) {
      projection = x;
      return path;
    };
  
    path.pointRadius = function(x) {
      if (typeof x === "function") pointRadius = x;
      else {
        pointRadius = +x;
        pointCircle = d3_path_circle(pointRadius);
      }
      return path;
    };
  
    return path;
  };
  
  function d3_path_circle(radius) {
    return "m0," + radius
        + "a" + radius + "," + radius + " 0 1,1 0," + (-2 * radius)
        + "a" + radius + "," + radius + " 0 1,1 0," + (+2 * radius)
        + "z";
  }
  /**
   * Given a GeoJSON object, returns the corresponding bounding box. The bounding
   * box is represented by a two-dimensional array: [[left, bottom], [right,
   * top]], where left is the minimum longitude, bottom is the minimum latitude,
   * right is maximum longitude, and top is the maximum latitude.
   */
  d3.geo.bounds = function(feature) {
    var left = Infinity,
        bottom = Infinity,
        right = -Infinity,
        top = -Infinity;
    d3_geo_bounds(feature, function(x, y) {
      if (x < left) left = x;
      if (x > right) right = x;
      if (y < bottom) bottom = y;
      if (y > top) top = y;
    });
    return [[left, bottom], [right, top]];
  };
  
  function d3_geo_bounds(o, f) {
    if (d3_geo_boundsTypes.hasOwnProperty(o.type)) d3_geo_boundsTypes[o.type](o, f);
  }
  
  var d3_geo_boundsTypes = {
    Feature: d3_geo_boundsFeature,
    FeatureCollection: d3_geo_boundsFeatureCollection,
    GeometryCollection: d3_geo_boundsGeometryCollection,
    LineString: d3_geo_boundsLineString,
    MultiLineString: d3_geo_boundsMultiLineString,
    MultiPoint: d3_geo_boundsLineString,
    MultiPolygon: d3_geo_boundsMultiPolygon,
    Point: d3_geo_boundsPoint,
    Polygon: d3_geo_boundsPolygon
  };
  
  function d3_geo_boundsFeature(o, f) {
    d3_geo_bounds(o.geometry, f);
  }
  
  function d3_geo_boundsFeatureCollection(o, f) {
    for (var a = o.features, i = 0, n = a.length; i < n; i++) {
      d3_geo_bounds(a[i].geometry, f);
    }
  }
  
  function d3_geo_boundsGeometryCollection(o, f) {
    for (var a = o.geometries, i = 0, n = a.length; i < n; i++) {
      d3_geo_bounds(a[i], f);
    }
  }
  
  function d3_geo_boundsLineString(o, f) {
    for (var a = o.coordinates, i = 0, n = a.length; i < n; i++) {
      f.apply(null, a[i]);
    }
  }
  
  function d3_geo_boundsMultiLineString(o, f) {
    for (var a = o.coordinates, i = 0, n = a.length; i < n; i++) {
      for (var b = a[i], j = 0, m = b.length; j < m; j++) {
        f.apply(null, b[j]);
      }
    }
  }
  
  function d3_geo_boundsMultiPolygon(o, f) {
    for (var a = o.coordinates, i = 0, n = a.length; i < n; i++) {
      for (var b = a[i][0], j = 0, m = b.length; j < m; j++) {
        f.apply(null, b[j]);
      }
    }
  }
  
  function d3_geo_boundsPoint(o, f) {
    f.apply(null, o.coordinates);
  }
  
  function d3_geo_boundsPolygon(o, f) {
    for (var a = o.coordinates[0], i = 0, n = a.length; i < n; i++) {
      f.apply(null, a[i]);
    }
  }
  // TODO breakAtDateLine?
  
  d3.geo.circle = function() {
    var origin = [0, 0],
        degrees = 90 - 1e-2,
        radians = degrees * d3_geo_radians,
        arc = d3.geo.greatArc().target(Object);
  
    function circle() {
      // TODO render a circle as a Polygon
    }
  
    function visible(point) {
      return arc.distance(point) < radians;
    }
  
    circle.clip = function(d) {
      arc.source(typeof origin === "function" ? origin.apply(this, arguments) : origin);
      return clipType(d);
    };
  
    var clipType = d3_geo_type({
  
      FeatureCollection: function(o) {
        var features = o.features.map(clipType).filter(Object);
        return features && (o = Object.create(o), o.features = features, o);
      },
  
      Feature: function(o) {
        var geometry = clipType(o.geometry);
        return geometry && (o = Object.create(o), o.geometry = geometry, o);
      },
  
      Point: function(o) {
        return visible(o.coordinates) && o;
      },
  
      MultiPoint: function(o) {
        var coordinates = o.coordinates.filter(visible);
        return coordinates.length && {
          type: o.type,
          coordinates: coordinates
        };
      },
  
      LineString: function(o) {
        var coordinates = clip(o.coordinates);
        return coordinates.length && (o = Object.create(o), o.coordinates = coordinates, o);
      },
  
      MultiLineString: function(o) {
        var coordinates = o.coordinates.map(clip).filter(function(d) { return d.length; });
        return coordinates.length && (o = Object.create(o), o.coordinates = coordinates, o);
      },
  
      Polygon: function(o) {
        var coordinates = o.coordinates.map(clip);
        return coordinates[0].length && (o = Object.create(o), o.coordinates = coordinates, o);
      },
  
      MultiPolygon: function(o) {
        var coordinates = o.coordinates.map(function(d) { return d.map(clip); }).filter(function(d) { return d[0].length; });
        return coordinates.length && (o = Object.create(o), o.coordinates = coordinates, o);
      },
  
      GeometryCollection: function(o) {
        var geometries = o.geometries.map(clipType).filter(Object);
        return geometries.length && (o = Object.create(o), o.geometries = geometries, o);
      }
  
    });
  
    function clip(coordinates) {
      var i = -1,
          n = coordinates.length,
          clipped = [],
          p0,
          p1,
          p2,
          d0,
          d1;
  
      while (++i < n) {
        d1 = arc.distance(p2 = coordinates[i]);
        if (d1 < radians) {
          if (p1) clipped.push(d3_geo_greatArcInterpolate(p1, p2)((d0 - radians) / (d0 - d1)));
          clipped.push(p2);
          p0 = p1 = null;
        } else {
          p1 = p2;
          if (!p0 && clipped.length) {
            clipped.push(d3_geo_greatArcInterpolate(clipped[clipped.length - 1], p1)((radians - d0) / (d1 - d0)));
            p0 = p1;
          }
        }
        d0 = d1;
      }
  
      if (p1 && clipped.length) {
        d1 = arc.distance(p2 = clipped[0]);
        clipped.push(d3_geo_greatArcInterpolate(p1, p2)((d0 - radians) / (d0 - d1)));
      }
  
      return resample(clipped);
    }
  
    // Resample coordinates, creating great arcs between each.
    function resample(coordinates) {
      var i = 0,
          n = coordinates.length,
          j,
          m,
          resampled = n ? [coordinates[0]] : coordinates,
          resamples,
          origin = arc.source();
  
      while (++i < n) {
        resamples = arc.source(coordinates[i - 1])(coordinates[i]).coordinates;
        for (j = 0, m = resamples.length; ++j < m;) resampled.push(resamples[j]);
      }
  
      arc.source(origin);
      return resampled;
    }
  
    circle.origin = function(x) {
      if (!arguments.length) return origin;
      origin = x;
      return circle;
    };
  
    circle.angle = function(x) {
      if (!arguments.length) return degrees;
      radians = (degrees = +x) * d3_geo_radians;
      return circle;
    };
  
    // Precision is specified in degrees.
    circle.precision = function(x) {
      if (!arguments.length) return arc.precision();
      arc.precision(x);
      return circle;
    };
  
    return circle;
  }
  d3.geo.greatArc = function() {
    var source = d3_geo_greatArcSource,
        target = d3_geo_greatArcTarget,
        precision = 6 * d3_geo_radians;
  
    function greatArc() {
      var a = typeof source === "function" ? source.apply(this, arguments) : source,
          b = typeof target === "function" ? target.apply(this, arguments) : target,
          i = d3_geo_greatArcInterpolate(a, b),
          dt = precision / i.d,
          t = 0,
          coordinates = [a];
      while ((t += dt) < 1) coordinates.push(i(t));
      coordinates.push(b);
      return {
        type: "LineString",
        coordinates: coordinates
      };
    }
  
    // Length returned in radians; multiply by radius for distance.
    greatArc.distance = function() {
      var a = typeof source === "function" ? source.apply(this, arguments) : source,
          b = typeof target === "function" ? target.apply(this, arguments) : target;
       return d3_geo_greatArcInterpolate(a, b).d;
    };
  
    greatArc.source = function(x) {
      if (!arguments.length) return source;
      source = x;
      return greatArc;
    };
  
    greatArc.target = function(x) {
      if (!arguments.length) return target;
      target = x;
      return greatArc;
    };
  
    // Precision is specified in degrees.
    greatArc.precision = function(x) {
      if (!arguments.length) return precision / d3_geo_radians;
      precision = x * d3_geo_radians;
      return greatArc;
    };
  
    return greatArc;
  };
  
  function d3_geo_greatArcSource(d) {
    return d.source;
  }
  
  function d3_geo_greatArcTarget(d) {
    return d.target;
  }
  
  function d3_geo_greatArcInterpolate(a, b) {
    var x0 = a[0] * d3_geo_radians, cx0 = Math.cos(x0), sx0 = Math.sin(x0),
        y0 = a[1] * d3_geo_radians, cy0 = Math.cos(y0), sy0 = Math.sin(y0),
        x1 = b[0] * d3_geo_radians, cx1 = Math.cos(x1), sx1 = Math.sin(x1),
        y1 = b[1] * d3_geo_radians, cy1 = Math.cos(y1), sy1 = Math.sin(y1),
        d = interpolate.d = Math.acos(Math.max(-1, Math.min(1, sy0 * sy1 + cy0 * cy1 * Math.cos(x1 - x0)))),
        sd = Math.sin(d);
  
    // From http://williams.best.vwh.net/avform.htm#Intermediate
    function interpolate(t) {
      var A = Math.sin(d - (t *= d)) / sd,
          B = Math.sin(t) / sd,
          x = A * cy0 * cx0 + B * cy1 * cx1,
          y = A * cy0 * sx0 + B * cy1 * sx1,
          z = A * sy0       + B * sy1;
      return [
        Math.atan2(y, x) / d3_geo_radians,
        Math.atan2(z, Math.sqrt(x * x + y * y)) / d3_geo_radians
      ];
    }
  
    return interpolate;
  }
  d3.geo.greatCircle = d3.geo.circle;
  d3.geom = {};
  /**
   * Computes a contour for a given input grid function using the <a
   * href="http://en.wikipedia.org/wiki/Marching_squares">marching
   * squares</a> algorithm. Returns the contour polygon as an array of points.
   *
   * @param grid a two-input function(x, y) that returns true for values
   * inside the contour and false for values outside the contour.
   * @param start an optional starting point [x, y] on the grid.
   * @returns polygon [[x1, y1], [x2, y2], …]
   */
  d3.geom.contour = function(grid, start) {
    var s = start || d3_geom_contourStart(grid), // starting point
        c = [],    // contour polygon
        x = s[0],  // current x position
        y = s[1],  // current y position
        dx = 0,    // next x direction
        dy = 0,    // next y direction
        pdx = NaN, // previous x direction
        pdy = NaN, // previous y direction
        i = 0;
  
    do {
      // determine marching squares index
      i = 0;
      if (grid(x-1, y-1)) i += 1;
      if (grid(x,   y-1)) i += 2;
      if (grid(x-1, y  )) i += 4;
      if (grid(x,   y  )) i += 8;
  
      // determine next direction
      if (i === 6) {
        dx = pdy === -1 ? -1 : 1;
        dy = 0;
      } else if (i === 9) {
        dx = 0;
        dy = pdx === 1 ? -1 : 1;
      } else {
        dx = d3_geom_contourDx[i];
        dy = d3_geom_contourDy[i];
      }
  
      // update contour polygon
      if (dx != pdx && dy != pdy) {
        c.push([x, y]);
        pdx = dx;
        pdy = dy;
      }
  
      x += dx;
      y += dy;
    } while (s[0] != x || s[1] != y);
  
    return c;
  };
  
  // lookup tables for marching directions
  var d3_geom_contourDx = [1, 0, 1, 1,-1, 0,-1, 1,0, 0,0,0,-1, 0,-1,NaN],
      d3_geom_contourDy = [0,-1, 0, 0, 0,-1, 0, 0,1,-1,1,1, 0,-1, 0,NaN];
  
  function d3_geom_contourStart(grid) {
    var x = 0,
        y = 0;
  
    // search for a starting point; begin at origin
    // and proceed along outward-expanding diagonals
    while (true) {
      if (grid(x,y)) {
        return [x,y];
      }
      if (x === 0) {
        x = y + 1;
        y = 0;
      } else {
        x = x - 1;
        y = y + 1;
      }
    }
  }
  /**
   * Computes the 2D convex hull of a set of points using Graham's scanning
   * algorithm. The algorithm has been implemented as described in Cormen,
   * Leiserson, and Rivest's Introduction to Algorithms. The running time of
   * this algorithm is O(n log n), where n is the number of input points.
   *
   * @param vertices [[x1, y1], [x2, y2], …]
   * @returns polygon [[x1, y1], [x2, y2], …]
   */
  d3.geom.hull = function(vertices) {
    if (vertices.length < 3) return [];
  
    var len = vertices.length,
        plen = len - 1,
        points = [],
        stack = [],
        i, j, h = 0, x1, y1, x2, y2, u, v, a, sp;
  
    // find the starting ref point: leftmost point with the minimum y coord
    for (i=1; i<len; ++i) {
      if (vertices[i][1] < vertices[h][1]) {
        h = i;
      } else if (vertices[i][1] == vertices[h][1]) {
        h = (vertices[i][0] < vertices[h][0] ? i : h);
      }
    }
  
    // calculate polar angles from ref point and sort
    for (i=0; i<len; ++i) {
      if (i === h) continue;
      y1 = vertices[i][1] - vertices[h][1];
      x1 = vertices[i][0] - vertices[h][0];
      points.push({angle: Math.atan2(y1, x1), index: i});
    }
    points.sort(function(a, b) { return a.angle - b.angle; });
  
    // toss out duplicate angles
    a = points[0].angle;
    v = points[0].index;
    u = 0;
    for (i=1; i<plen; ++i) {
      j = points[i].index;
      if (a == points[i].angle) {
        // keep angle for point most distant from the reference
        x1 = vertices[v][0] - vertices[h][0];
        y1 = vertices[v][1] - vertices[h][1];
        x2 = vertices[j][0] - vertices[h][0];
        y2 = vertices[j][1] - vertices[h][1];
        if ((x1*x1 + y1*y1) >= (x2*x2 + y2*y2)) {
          points[i].index = -1;
        } else {
          points[u].index = -1;
          a = points[i].angle;
          u = i;
          v = j;
        }
      } else {
        a = points[i].angle;
        u = i;
        v = j;
      }
    }
  
    // initialize the stack
    stack.push(h);
    for (i=0, j=0; i<2; ++j) {
      if (points[j].index !== -1) {
        stack.push(points[j].index);
        i++;
      }
    }
    sp = stack.length;
  
    // do graham's scan
    for (; j<plen; ++j) {
      if (points[j].index === -1) continue; // skip tossed out points
      while (!d3_geom_hullCCW(stack[sp-2], stack[sp-1], points[j].index, vertices)) {
        --sp;
      }
      stack[sp++] = points[j].index;
    }
  
    // construct the hull
    var poly = [];
    for (i=0; i<sp; ++i) {
      poly.push(vertices[stack[i]]);
    }
    return poly;
  }
  
  // are three points in counter-clockwise order?
  function d3_geom_hullCCW(i1, i2, i3, v) {
    var t, a, b, c, d, e, f;
    t = v[i1]; a = t[0]; b = t[1];
    t = v[i2]; c = t[0]; d = t[1];
    t = v[i3]; e = t[0]; f = t[1];
    return ((f-b)*(c-a) - (d-b)*(e-a)) > 0;
  }
  // Note: requires coordinates to be counterclockwise and convex!
  d3.geom.polygon = function(coordinates) {
  
    coordinates.area = function() {
      var i = 0,
          n = coordinates.length,
          a = coordinates[n - 1][0] * coordinates[0][1],
          b = coordinates[n - 1][1] * coordinates[0][0];
      while (++i < n) {
        a += coordinates[i - 1][0] * coordinates[i][1];
        b += coordinates[i - 1][1] * coordinates[i][0];
      }
      return (b - a) * .5;
    };
  
    coordinates.centroid = function(k) {
      var i = -1,
          n = coordinates.length,
          x = 0,
          y = 0,
          a,
          b = coordinates[n - 1],
          c;
      if (!arguments.length) k = -1 / (6 * coordinates.area());
      while (++i < n) {
        a = b;
        b = coordinates[i];
        c = a[0] * b[1] - b[0] * a[1];
        x += (a[0] + b[0]) * c;
        y += (a[1] + b[1]) * c;
      }
      return [x * k, y * k];
    };
  
    // The Sutherland-Hodgman clipping algorithm.
    coordinates.clip = function(subject) {
      var input,
          i = -1,
          n = coordinates.length,
          j,
          m,
          a = coordinates[n - 1],
          b,
          c,
          d;
      while (++i < n) {
        input = subject.slice();
        subject.length = 0;
        b = coordinates[i];
        c = input[(m = input.length) - 1];
        j = -1;
        while (++j < m) {
          d = input[j];
          if (d3_geom_polygonInside(d, a, b)) {
            if (!d3_geom_polygonInside(c, a, b)) {
              subject.push(d3_geom_polygonIntersect(c, d, a, b));
            }
            subject.push(d);
          } else if (d3_geom_polygonInside(c, a, b)) {
            subject.push(d3_geom_polygonIntersect(c, d, a, b));
          }
          c = d;
        }
        a = b;
      }
      return subject;
    };
  
    return coordinates;
  };
  
  function d3_geom_polygonInside(p, a, b) {
    return (b[0] - a[0]) * (p[1] - a[1]) < (b[1] - a[1]) * (p[0] - a[0]);
  }
  
  // Intersect two infinite lines cd and ab.
  function d3_geom_polygonIntersect(c, d, a, b) {
    var x1 = c[0], x2 = d[0], x3 = a[0], x4 = b[0],
        y1 = c[1], y2 = d[1], y3 = a[1], y4 = b[1],
        x13 = x1 - x3,
        x21 = x2 - x1,
        x43 = x4 - x3,
        y13 = y1 - y3,
        y21 = y2 - y1,
        y43 = y4 - y3,
        ua = (x43 * y13 - y43 * x13) / (y43 * x21 - x43 * y21);
    return [x1 + ua * x21, y1 + ua * y21];
  }
  // Adapted from Nicolas Garcia Belmonte's JIT implementation:
  // http://blog.thejit.org/2010/02/12/voronoi-tessellation/
  // http://blog.thejit.org/assets/voronoijs/voronoi.js
  // See lib/jit/LICENSE for details.
  
  // Notes:
  //
  // This implementation does not clip the returned polygons, so if you want to
  // clip them to a particular shape you will need to do that either in SVG or by
  // post-processing with d3.geom.polygon's clip method.
  //
  // If any vertices are coincident or have NaN positions, the behavior of this
  // method is undefined. Most likely invalid polygons will be returned. You
  // should filter invalid points, and consolidate coincident points, before
  // computing the tessellation.
  
  /**
   * @param vertices [[x1, y1], [x2, y2], …]
   * @returns polygons [[[x1, y1], [x2, y2], …], …]
   */
  d3.geom.voronoi = function(vertices) {
    var polygons = vertices.map(function() { return []; });
  
    d3_voronoi_tessellate(vertices, function(e) {
      var s1,
          s2,
          x1,
          x2,
          y1,
          y2;
      if (e.a === 1 && e.b >= 0) {
        s1 = e.ep.r;
        s2 = e.ep.l;
      } else {
        s1 = e.ep.l;
        s2 = e.ep.r;
      }
      if (e.a === 1) {
        y1 = s1 ? s1.y : -1e6;
        x1 = e.c - e.b * y1;
        y2 = s2 ? s2.y : 1e6;
        x2 = e.c - e.b * y2;
      } else {
        x1 = s1 ? s1.x : -1e6;
        y1 = e.c - e.a * x1;
        x2 = s2 ? s2.x : 1e6;
        y2 = e.c - e.a * x2;
      }
      var v1 = [x1, y1],
          v2 = [x2, y2];
      polygons[e.region.l.index].push(v1, v2);
      polygons[e.region.r.index].push(v1, v2);
    });
  
    // Reconnect the polygon segments into counterclockwise loops.
    return polygons.map(function(polygon, i) {
      var cx = vertices[i][0],
          cy = vertices[i][1];
      polygon.forEach(function(v) {
        v.angle = Math.atan2(v[0] - cx, v[1] - cy);
      });
      return polygon.sort(function(a, b) {
        return a.angle - b.angle;
      }).filter(function(d, i) {
        return !i || (d.angle - polygon[i - 1].angle > 1e-10);
      });
    });
  };
  
  var d3_voronoi_opposite = {"l": "r", "r": "l"};
  
  function d3_voronoi_tessellate(vertices, callback) {
  
    var Sites = {
      list: vertices
        .map(function(v, i) {
          return {
            index: i,
            x: v[0],
            y: v[1]
          };
        })
        .sort(function(a, b) {
          return a.y < b.y ? -1
            : a.y > b.y ? 1
            : a.x < b.x ? -1
            : a.x > b.x ? 1
            : 0;
        }),
      bottomSite: null
    };
  
    var EdgeList = {
      list: [],
      leftEnd: null,
      rightEnd: null,
  
      init: function() {
        EdgeList.leftEnd = EdgeList.createHalfEdge(null, "l");
        EdgeList.rightEnd = EdgeList.createHalfEdge(null, "l");
        EdgeList.leftEnd.r = EdgeList.rightEnd;
        EdgeList.rightEnd.l = EdgeList.leftEnd;
        EdgeList.list.unshift(EdgeList.leftEnd, EdgeList.rightEnd);
      },
  
      createHalfEdge: function(edge, side) {
        return {
          edge: edge,
          side: side,
          vertex: null,
          "l": null,
          "r": null
        };
      },
  
      insert: function(lb, he) {
        he.l = lb;
        he.r = lb.r;
        lb.r.l = he;
        lb.r = he;
      },
  
      leftBound: function(p) {
        var he = EdgeList.leftEnd;
        do {
          he = he.r;
        } while (he != EdgeList.rightEnd && Geom.rightOf(he, p));
        he = he.l;
        return he;
      },
  
      del: function(he) {
        he.l.r = he.r;
        he.r.l = he.l;
        he.edge = null;
      },
  
      right: function(he) {
        return he.r;
      },
  
      left: function(he) {
        return he.l;
      },
  
      leftRegion: function(he) {
        return he.edge == null
            ? Sites.bottomSite
            : he.edge.region[he.side];
      },
  
      rightRegion: function(he) {
        return he.edge == null
            ? Sites.bottomSite
            : he.edge.region[d3_voronoi_opposite[he.side]];
      }
    };
  
    var Geom = {
  
      bisect: function(s1, s2) {
        var newEdge = {
          region: {"l": s1, "r": s2},
          ep: {"l": null, "r": null}
        };
  
        var dx = s2.x - s1.x,
            dy = s2.y - s1.y,
            adx = dx > 0 ? dx : -dx,
            ady = dy > 0 ? dy : -dy;
  
        newEdge.c = s1.x * dx + s1.y * dy
            + (dx * dx + dy * dy) * .5;
  
        if (adx > ady) {
          newEdge.a = 1;
          newEdge.b = dy / dx;
          newEdge.c /= dx;
        } else {
          newEdge.b = 1;
          newEdge.a = dx / dy;
          newEdge.c /= dy;
        }
  
        return newEdge;
      },
  
      intersect: function(el1, el2) {
        var e1 = el1.edge,
            e2 = el2.edge;
        if (!e1 || !e2 || (e1.region.r == e2.region.r)) {
          return null;
        }
        var d = (e1.a * e2.b) - (e1.b * e2.a);
        if (Math.abs(d) < 1e-10) {
          return null;
        }
        var xint = (e1.c * e2.b - e2.c * e1.b) / d,
            yint = (e2.c * e1.a - e1.c * e2.a) / d,
            e1r = e1.region.r,
            e2r = e2.region.r,
            el,
            e;
        if ((e1r.y < e2r.y) ||
           (e1r.y == e2r.y && e1r.x < e2r.x)) {
          el = el1;
          e = e1;
        } else {
          el = el2;
          e = e2;
        }
        var rightOfSite = (xint >= e.region.r.x);
        if ((rightOfSite && (el.side === "l")) ||
          (!rightOfSite && (el.side === "r"))) {
          return null;
        }
        return {
          x: xint,
          y: yint
        };
      },
  
      rightOf: function(he, p) {
        var e = he.edge,
            topsite = e.region.r,
            rightOfSite = (p.x > topsite.x);
  
        if (rightOfSite && (he.side === "l")) {
          return 1;
        }
        if (!rightOfSite && (he.side === "r")) {
          return 0;
        }
        if (e.a === 1) {
          var dyp = p.y - topsite.y,
              dxp = p.x - topsite.x,
              fast = 0,
              above = 0;
  
          if ((!rightOfSite && (e.b < 0)) ||
            (rightOfSite && (e.b >= 0))) {
            above = fast = (dyp >= e.b * dxp);
          } else {
            above = ((p.x + p.y * e.b) > e.c);
            if (e.b < 0) {
              above = !above;
            }
            if (!above) {
              fast = 1;
            }
          }
          if (!fast) {
            var dxs = topsite.x - e.region.l.x;
            above = (e.b * (dxp * dxp - dyp * dyp)) <
              (dxs * dyp * (1 + 2 * dxp / dxs + e.b * e.b));
  
            if (e.b < 0) {
              above = !above;
            }
          }
        } else /* e.b == 1 */ {
          var yl = e.c - e.a * p.x,
              t1 = p.y - yl,
              t2 = p.x - topsite.x,
              t3 = yl - topsite.y;
  
          above = (t1 * t1) > (t2 * t2 + t3 * t3);
        }
        return he.side === "l" ? above : !above;
      },
  
      endPoint: function(edge, side, site) {
        edge.ep[side] = site;
        if (!edge.ep[d3_voronoi_opposite[side]]) return;
        callback(edge);
      },
  
      distance: function(s, t) {
        var dx = s.x - t.x,
            dy = s.y - t.y;
        return Math.sqrt(dx * dx + dy * dy);
      }
    };
  
    var EventQueue = {
      list: [],
  
      insert: function(he, site, offset) {
        he.vertex = site;
        he.ystar = site.y + offset;
        for (var i=0, list=EventQueue.list, l=list.length; i<l; i++) {
          var next = list[i];
          if (he.ystar > next.ystar ||
            (he.ystar == next.ystar &&
            site.x > next.vertex.x)) {
            continue;
          } else {
            break;
          }
        }
        list.splice(i, 0, he);
      },
  
      del: function(he) {
        for (var i=0, ls=EventQueue.list, l=ls.length; i<l && (ls[i] != he); ++i) {}
        ls.splice(i, 1);
      },
  
      empty: function() { return EventQueue.list.length === 0; },
  
      nextEvent: function(he) {
        for (var i=0, ls=EventQueue.list, l=ls.length; i<l; ++i) {
          if (ls[i] == he) return ls[i+1];
        }
        return null;
      },
  
      min: function() {
        var elem = EventQueue.list[0];
        return {
          x: elem.vertex.x,
          y: elem.ystar
        };
      },
  
      extractMin: function() {
        return EventQueue.list.shift();
      }
    };
  
    EdgeList.init();
    Sites.bottomSite = Sites.list.shift();
  
    var newSite = Sites.list.shift(), newIntStar;
    var lbnd, rbnd, llbnd, rrbnd, bisector;
    var bot, top, temp, p, v;
    var e, pm;
  
    while (true) {
      if (!EventQueue.empty()) {
        newIntStar = EventQueue.min();
      }
      if (newSite && (EventQueue.empty()
        || newSite.y < newIntStar.y
        || (newSite.y == newIntStar.y
        && newSite.x < newIntStar.x))) { //new site is smallest
        lbnd = EdgeList.leftBound(newSite);
        rbnd = EdgeList.right(lbnd);
        bot = EdgeList.rightRegion(lbnd);
        e = Geom.bisect(bot, newSite);
        bisector = EdgeList.createHalfEdge(e, "l");
        EdgeList.insert(lbnd, bisector);
        p = Geom.intersect(lbnd, bisector);
        if (p) {
          EventQueue.del(lbnd);
          EventQueue.insert(lbnd, p, Geom.distance(p, newSite));
        }
        lbnd = bisector;
        bisector = EdgeList.createHalfEdge(e, "r");
        EdgeList.insert(lbnd, bisector);
        p = Geom.intersect(bisector, rbnd);
        if (p) {
          EventQueue.insert(bisector, p, Geom.distance(p, newSite));
        }
        newSite = Sites.list.shift();
      } else if (!EventQueue.empty()) { //intersection is smallest
        lbnd = EventQueue.extractMin();
        llbnd = EdgeList.left(lbnd);
        rbnd = EdgeList.right(lbnd);
        rrbnd = EdgeList.right(rbnd);
        bot = EdgeList.leftRegion(lbnd);
        top = EdgeList.rightRegion(rbnd);
        v = lbnd.vertex;
        Geom.endPoint(lbnd.edge, lbnd.side, v);
        Geom.endPoint(rbnd.edge, rbnd.side, v);
        EdgeList.del(lbnd);
        EventQueue.del(rbnd);
        EdgeList.del(rbnd);
        pm = "l";
        if (bot.y > top.y) {
          temp = bot;
          bot = top;
          top = temp;
          pm = "r";
        }
        e = Geom.bisect(bot, top);
        bisector = EdgeList.createHalfEdge(e, pm);
        EdgeList.insert(llbnd, bisector);
        Geom.endPoint(e, d3_voronoi_opposite[pm], v);
        p = Geom.intersect(llbnd, bisector);
        if (p) {
          EventQueue.del(llbnd);
          EventQueue.insert(llbnd, p, Geom.distance(p, bot));
        }
        p = Geom.intersect(bisector, rrbnd);
        if (p) {
          EventQueue.insert(bisector, p, Geom.distance(p, bot));
        }
      } else {
        break;
      }
    }//end while
  
    for (lbnd = EdgeList.right(EdgeList.leftEnd);
        lbnd != EdgeList.rightEnd;
        lbnd = EdgeList.right(lbnd)) {
      callback(lbnd.edge);
    }
  }
  /**
  * @param vertices [[x1, y1], [x2, y2], …]
  * @returns triangles [[[x1, y1], [x2, y2], [x3, y3]], …]
   */
  d3.geom.delaunay = function(vertices) {
    var edges = vertices.map(function() { return []; }),
        triangles = [];
  
    // Use the Voronoi tessellation to determine Delaunay edges.
    d3_voronoi_tessellate(vertices, function(e) {
      edges[e.region.l.index].push(vertices[e.region.r.index]);
    });
  
    // Reconnect the edges into counterclockwise triangles.
    edges.forEach(function(edge, i) {
      var v = vertices[i],
          cx = v[0],
          cy = v[1];
      edge.forEach(function(v) {
        v.angle = Math.atan2(v[0] - cx, v[1] - cy);
      });
      edge.sort(function(a, b) {
        return a.angle - b.angle;
      });
      for (var j = 0, m = edge.length - 1; j < m; j++) {
        triangles.push([v, edge[j], edge[j + 1]]);
      }
    });
  
    return triangles;
  };
  // Constructs a new quadtree for the specified array of points. A quadtree is a
  // two-dimensional recursive spatial subdivision. This implementation uses
  // square partitions, dividing each square into four equally-sized squares. Each
  // point exists in a unique node; if multiple points are in the same position,
  // some points may be stored on internal nodes rather than leaf nodes. Quadtrees
  // can be used to accelerate various spatial operations, such as the Barnes-Hut
  // approximation for computing n-body forces, or collision detection.
  d3.geom.quadtree = function(points, x1, y1, x2, y2) {
    var p,
        i = -1,
        n = points.length;
  
    // Type conversion for deprecated API.
    if (n && isNaN(points[0].x)) points = points.map(d3_geom_quadtreePoint);
  
    // Allow bounds to be specified explicitly.
    if (arguments.length < 5) {
      if (arguments.length === 3) {
        y2 = x2 = y1;
        y1 = x1;
      } else {
        x1 = y1 = Infinity;
        x2 = y2 = -Infinity;
  
        // Compute bounds.
        while (++i < n) {
          p = points[i];
          if (p.x < x1) x1 = p.x;
          if (p.y < y1) y1 = p.y;
          if (p.x > x2) x2 = p.x;
          if (p.y > y2) y2 = p.y;
        }
  
        // Squarify the bounds.
        var dx = x2 - x1,
            dy = y2 - y1;
        if (dx > dy) y2 = y1 + dx;
        else x2 = x1 + dy;
      }
    }
  
    // Recursively inserts the specified point p at the node n or one of its
    // descendants. The bounds are defined by [x1, x2] and [y1, y2].
    function insert(n, p, x1, y1, x2, y2) {
      if (isNaN(p.x) || isNaN(p.y)) return; // ignore invalid points
      if (n.leaf) {
        var v = n.point;
        if (v) {
          // If the point at this leaf node is at the same position as the new
          // point we are adding, we leave the point associated with the
          // internal node while adding the new point to a child node. This
          // avoids infinite recursion.
          if ((Math.abs(v.x - p.x) + Math.abs(v.y - p.y)) < .01) {
            insertChild(n, p, x1, y1, x2, y2);
          } else {
            n.point = null;
            insertChild(n, v, x1, y1, x2, y2);
            insertChild(n, p, x1, y1, x2, y2);
          }
        } else {
          n.point = p;
        }
      } else {
        insertChild(n, p, x1, y1, x2, y2);
      }
    }
  
    // Recursively inserts the specified point p into a descendant of node n. The
    // bounds are defined by [x1, x2] and [y1, y2].
    function insertChild(n, p, x1, y1, x2, y2) {
      // Compute the split point, and the quadrant in which to insert p.
      var sx = (x1 + x2) * .5,
          sy = (y1 + y2) * .5,
          right = p.x >= sx,
          bottom = p.y >= sy,
          i = (bottom << 1) + right;
  
      // Recursively insert into the child node.
      n.leaf = false;
      n = n.nodes[i] || (n.nodes[i] = d3_geom_quadtreeNode());
  
      // Update the bounds as we recurse.
      if (right) x1 = sx; else x2 = sx;
      if (bottom) y1 = sy; else y2 = sy;
      insert(n, p, x1, y1, x2, y2);
    }
  
    // Create the root node.
    var root = d3_geom_quadtreeNode();
  
    root.add = function(p) {
      insert(root, p, x1, y1, x2, y2);
    };
  
    root.visit = function(f) {
      d3_geom_quadtreeVisit(f, root, x1, y1, x2, y2);
    };
  
    // Insert all points.
    points.forEach(root.add);
    return root;
  };
  
  function d3_geom_quadtreeNode() {
    return {
      leaf: true,
      nodes: [],
      point: null
    };
  }
  
  function d3_geom_quadtreeVisit(f, node, x1, y1, x2, y2) {
    if (!f(node, x1, y1, x2, y2)) {
      var sx = (x1 + x2) * .5,
          sy = (y1 + y2) * .5,
          children = node.nodes;
      if (children[0]) d3_geom_quadtreeVisit(f, children[0], x1, y1, sx, sy);
      if (children[1]) d3_geom_quadtreeVisit(f, children[1], sx, y1, x2, sy);
      if (children[2]) d3_geom_quadtreeVisit(f, children[2], x1, sy, sx, y2);
      if (children[3]) d3_geom_quadtreeVisit(f, children[3], sx, sy, x2, y2);
    }
  }
  
  function d3_geom_quadtreePoint(p) {
    return {
      x: p[0],
      y: p[1]
    };
  }
  d3.time = {};
  
  var d3_time = Date;
  
  function d3_time_utc() {
    this._ = new Date(arguments.length > 1
        ? Date.UTC.apply(this, arguments)
        : arguments[0]);
  }
  
  d3_time_utc.prototype = {
    getDate: function() { return this._.getUTCDate(); },
    getDay: function() { return this._.getUTCDay(); },
    getFullYear: function() { return this._.getUTCFullYear(); },
    getHours: function() { return this._.getUTCHours(); },
    getMilliseconds: function() { return this._.getUTCMilliseconds(); },
    getMinutes: function() { return this._.getUTCMinutes(); },
    getMonth: function() { return this._.getUTCMonth(); },
    getSeconds: function() { return this._.getUTCSeconds(); },
    getTime: function() { return this._.getTime(); },
    getTimezoneOffset: function() { return 0; },
    valueOf: function() { return this._.valueOf(); },
    setDate: function() { d3_time_prototype.setUTCDate.apply(this._, arguments); },
    setDay: function() { d3_time_prototype.setUTCDay.apply(this._, arguments); },
    setFullYear: function() { d3_time_prototype.setUTCFullYear.apply(this._, arguments); },
    setHours: function() { d3_time_prototype.setUTCHours.apply(this._, arguments); },
    setMilliseconds: function() { d3_time_prototype.setUTCMilliseconds.apply(this._, arguments); },
    setMinutes: function() { d3_time_prototype.setUTCMinutes.apply(this._, arguments); },
    setMonth: function() { d3_time_prototype.setUTCMonth.apply(this._, arguments); },
    setSeconds: function() { d3_time_prototype.setUTCSeconds.apply(this._, arguments); },
    setTime: function() { d3_time_prototype.setTime.apply(this._, arguments); }
  };
  
  var d3_time_prototype = Date.prototype;
  d3.time.format = function(template) {
    var n = template.length;
  
    function format(date) {
      var string = [],
          i = -1,
          j = 0,
          c,
          f;
      while (++i < n) {
        if (template.charCodeAt(i) == 37) {
          string.push(
              template.substring(j, i),
              (f = d3_time_formats[c = template.charAt(++i)])
              ? f(date) : c);
          j = i + 1;
        }
      }
      string.push(template.substring(j, i));
      return string.join("");
    }
  
    format.parse = function(string) {
      var d = {y: 1900, m: 0, d: 1, H: 0, M: 0, S: 0, L: 0},
          i = d3_time_parse(d, template, string, 0);
      if (i != string.length) return null;
  
      // The am-pm flag is 0 for AM, and 1 for PM.
      if ("p" in d) d.H = d.H % 12 + d.p * 12;
  
      var date = new d3_time();
      date.setFullYear(d.y, d.m, d.d);
      date.setHours(d.H, d.M, d.S, d.L);
      return date;
    };
  
    format.toString = function() {
      return template;
    };
  
    return format;
  };
  
  function d3_time_parse(date, template, string, j) {
    var c,
        p,
        i = 0,
        n = template.length,
        m = string.length;
    while (i < n) {
      if (j >= m) return -1;
      c = template.charCodeAt(i++);
      if (c == 37) {
        p = d3_time_parsers[template.charAt(i++)];
        if (!p || ((j = p(date, string, j)) < 0)) return -1;
      } else if (c != string.charCodeAt(j++)) {
        return -1;
      }
    }
    return j;
  }
  
  var d3_time_zfill2 = d3.format("02d"),
      d3_time_zfill3 = d3.format("03d"),
      d3_time_zfill4 = d3.format("04d"),
      d3_time_sfill2 = d3.format("2d");
  
  var d3_time_formats = {
    a: function(d) { return d3_time_weekdays[d.getDay()].substring(0, 3); },
    A: function(d) { return d3_time_weekdays[d.getDay()]; },
    b: function(d) { return d3_time_months[d.getMonth()].substring(0, 3); },
    B: function(d) { return d3_time_months[d.getMonth()]; },
    c: d3.time.format("%a %b %e %H:%M:%S %Y"),
    d: function(d) { return d3_time_zfill2(d.getDate()); },
    e: function(d) { return d3_time_sfill2(d.getDate()); },
    H: function(d) { return d3_time_zfill2(d.getHours()); },
    I: function(d) { return d3_time_zfill2(d.getHours() % 12 || 12); },
    j: function(d) { return d3_time_zfill3(1 + d3.time.dayOfYear(d)); },
    L: function(d) { return d3_time_zfill3(d.getMilliseconds()); },
    m: function(d) { return d3_time_zfill2(d.getMonth() + 1); },
    M: function(d) { return d3_time_zfill2(d.getMinutes()); },
    p: function(d) { return d.getHours() >= 12 ? "PM" : "AM"; },
    S: function(d) { return d3_time_zfill2(d.getSeconds()); },
    U: function(d) { return d3_time_zfill2(d3.time.sundayOfYear(d)); },
    w: function(d) { return d.getDay(); },
    W: function(d) { return d3_time_zfill2(d3.time.mondayOfYear(d)); },
    x: d3.time.format("%m/%d/%y"),
    X: d3.time.format("%H:%M:%S"),
    y: function(d) { return d3_time_zfill2(d.getFullYear() % 100); },
    Y: function(d) { return d3_time_zfill4(d.getFullYear() % 10000); },
    Z: d3_time_zone,
    "%": function(d) { return "%"; }
  };
  
  var d3_time_parsers = {
    a: d3_time_parseWeekdayAbbrev,
    A: d3_time_parseWeekday,
    b: d3_time_parseMonthAbbrev,
    B: d3_time_parseMonth,
    c: d3_time_parseLocaleFull,
    d: d3_time_parseDay,
    e: d3_time_parseDay,
    H: d3_time_parseHour24,
    I: d3_time_parseHour24,
    // j: function(d, s, i) { /*TODO day of year [001,366] */ return i; },
    L: d3_time_parseMilliseconds,
    m: d3_time_parseMonthNumber,
    M: d3_time_parseMinutes,
    p: d3_time_parseAmPm,
    S: d3_time_parseSeconds,
    // U: function(d, s, i) { /*TODO week number (sunday) [00,53] */ return i; },
    // w: function(d, s, i) { /*TODO weekday [0,6] */ return i; },
    // W: function(d, s, i) { /*TODO week number (monday) [00,53] */ return i; },
    x: d3_time_parseLocaleDate,
    X: d3_time_parseLocaleTime,
    y: d3_time_parseYear,
    Y: d3_time_parseFullYear
    // ,
    // Z: function(d, s, i) { /*TODO time zone */ return i; },
    // "%": function(d, s, i) { /*TODO literal % */ return i; }
  };
  
  // Note: weekday is validated, but does not set the date.
  function d3_time_parseWeekdayAbbrev(date, string, i) {
    return d3_time_weekdayAbbrevRe.test(string.substring(i, i += 3)) ? i : -1;
  }
  
  // Note: weekday is validated, but does not set the date.
  function d3_time_parseWeekday(date, string, i) {
    d3_time_weekdayRe.lastIndex = 0;
    var n = d3_time_weekdayRe.exec(string.substring(i, i + 10));
    return n ? i += n[0].length : -1;
  }
  
  var d3_time_weekdayAbbrevRe = /^(?:sun|mon|tue|wed|thu|fri|sat)/i,
      d3_time_weekdayRe = /^(?:Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday)/i;
      d3_time_weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
  
  function d3_time_parseMonthAbbrev(date, string, i) {
    var n = d3_time_monthAbbrevLookup.get(string.substring(i, i += 3).toLowerCase());
    return n == null ? -1 : (date.m = n, i);
  }
  
  var d3_time_monthAbbrevLookup = d3.map({
    jan: 0,
    feb: 1,
    mar: 2,
    apr: 3,
    may: 4,
    jun: 5,
    jul: 6,
    aug: 7,
    sep: 8,
    oct: 9,
    nov: 10,
    dec: 11
  });
  
  function d3_time_parseMonth(date, string, i) {
    d3_time_monthRe.lastIndex = 0;
    var n = d3_time_monthRe.exec(string.substring(i, i + 12));
    return n ? (date.m = d3_time_monthLookup.get(n[0].toLowerCase()), i += n[0].length) : -1;
  }
  
  var d3_time_monthRe = /^(?:January|February|March|April|May|June|July|August|September|October|November|December)/ig;
  
  var d3_time_monthLookup = d3.map({
    january: 0,
    february: 1,
    march: 2,
    april: 3,
    may: 4,
    june: 5,
    july: 6,
    august: 7,
    september: 8,
    october: 9,
    november: 10,
    december: 11
  });
  
  var d3_time_months = [
    "January",
    "February",
    "March",
    "April",
    "May",
    "June",
    "July",
    "August",
    "September",
    "October",
    "November",
    "December"
  ];
  
  function d3_time_parseLocaleFull(date, string, i) {
    return d3_time_parse(date, d3_time_formats.c.toString(), string, i);
  }
  
  function d3_time_parseLocaleDate(date, string, i) {
    return d3_time_parse(date, d3_time_formats.x.toString(), string, i);
  }
  
  function d3_time_parseLocaleTime(date, string, i) {
    return d3_time_parse(date, d3_time_formats.X.toString(), string, i);
  }
  
  function d3_time_parseFullYear(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 4));
    return n ? (date.y = +n[0], i += n[0].length) : -1;
  }
  
  function d3_time_parseYear(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.y = d3_time_century() + +n[0], i += n[0].length) : -1;
  }
  
  function d3_time_century() {
    return ~~(new Date().getFullYear() / 1000) * 1000;
  }
  
  function d3_time_parseMonthNumber(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.m = n[0] - 1, i += n[0].length) : -1;
  }
  
  function d3_time_parseDay(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.d = +n[0], i += n[0].length) : -1;
  }
  
  // Note: we don't validate that the hour is in the range [0,23] or [1,12].
  function d3_time_parseHour24(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.H = +n[0], i += n[0].length) : -1;
  }
  
  function d3_time_parseMinutes(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.M = +n[0], i += n[0].length) : -1;
  }
  
  function d3_time_parseSeconds(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 2));
    return n ? (date.S = +n[0], i += n[0].length) : -1;
  }
  
  function d3_time_parseMilliseconds(date, string, i) {
    d3_time_numberRe.lastIndex = 0;
    var n = d3_time_numberRe.exec(string.substring(i, i + 3));
    return n ? (date.L = +n[0], i += n[0].length) : -1;
  }
  
  // Note: we don't look at the next directive.
  var d3_time_numberRe = /\s*\d+/;
  
  function d3_time_parseAmPm(date, string, i) {
    var n = d3_time_amPmLookup.get(string.substring(i, i += 2).toLowerCase());
    return n == null ? -1 : (date.p = n, i);
  }
  
  var d3_time_amPmLookup = d3.map({
    am: 0,
    pm: 1
  });
  
  // TODO table of time zone offset names?
  function d3_time_zone(d) {
    var z = d.getTimezoneOffset(),
        zs = z > 0 ? "-" : "+",
        zh = ~~(Math.abs(z) / 60),
        zm = Math.abs(z) % 60;
    return zs + d3_time_zfill2(zh) + d3_time_zfill2(zm);
  }
  d3.time.format.utc = function(template) {
    var local = d3.time.format(template);
  
    function format(date) {
      try {
        d3_time = d3_time_utc;
        var utc = new d3_time();
        utc._ = date;
        return local(utc);
      } finally {
        d3_time = Date;
      }
    }
  
    format.parse = function(string) {
      try {
        d3_time = d3_time_utc;
        var date = local.parse(string);
        return date && date._;
      } finally {
        d3_time = Date;
      }
    };
  
    format.toString = local.toString;
  
    return format;
  };
  var d3_time_formatIso = d3.time.format.utc("%Y-%m-%dT%H:%M:%S.%LZ");
  
  d3.time.format.iso = Date.prototype.toISOString ? d3_time_formatIsoNative : d3_time_formatIso;
  
  function d3_time_formatIsoNative(date) {
    return date.toISOString();
  }
  
  d3_time_formatIsoNative.parse = function(string) {
    return new Date(string);
  };
  
  d3_time_formatIsoNative.toString = d3_time_formatIso.toString;
  function d3_time_interval(local, step, number) {
  
    function round(date) {
      var d0 = local(date), d1 = offset(d0, 1);
      return date - d0 < d1 - date ? d0 : d1;
    }
  
    function ceil(date) {
      step(date = local(new d3_time(date - 1)), 1);
      return date;
    }
  
    function offset(date, k) {
      step(date = new d3_time(+date), k);
      return date;
    }
  
    function range(t0, t1, dt) {
      var time = ceil(t0), times = [];
      if (dt > 1) {
        while (time < t1) {
          if (!(number(time) % dt)) times.push(new Date(+time));
          step(time, 1);
        }
      } else {
        while (time < t1) times.push(new Date(+time)), step(time, 1);
      }
      return times;
    }
  
    function range_utc(t0, t1, dt) {
      try {
        d3_time = d3_time_utc;
        var utc = new d3_time_utc();
        utc._ = t0;
        return range(utc, t1, dt);
      } finally {
        d3_time = Date;
      }
    }
  
    local.floor = local;
    local.round = round;
    local.ceil = ceil;
    local.offset = offset;
    local.range = range;
  
    var utc = local.utc = d3_time_interval_utc(local);
    utc.floor = utc;
    utc.round = d3_time_interval_utc(round);
    utc.ceil = d3_time_interval_utc(ceil);
    utc.offset = d3_time_interval_utc(offset);
    utc.range = range_utc;
  
    return local;
  }
  
  function d3_time_interval_utc(method) {
    return function(date, k) {
      try {
        d3_time = d3_time_utc;
        var utc = new d3_time_utc();
        utc._ = date;
        return method(utc, k)._;
      } finally {
        d3_time = Date;
      }
    };
  }
  d3.time.second = d3_time_interval(function(date) {
    return new d3_time(Math.floor(date / 1e3) * 1e3);
  }, function(date, offset) {
    date.setTime(date.getTime() + Math.floor(offset) * 1e3); // DST breaks setSeconds
  }, function(date) {
    return date.getSeconds();
  });
  
  d3.time.seconds = d3.time.second.range;
  d3.time.seconds.utc = d3.time.second.utc.range;
  d3.time.minute = d3_time_interval(function(date) {
    return new d3_time(Math.floor(date / 6e4) * 6e4);
  }, function(date, offset) {
    date.setTime(date.getTime() + Math.floor(offset) * 6e4); // DST breaks setMinutes
  }, function(date) {
    return date.getMinutes();
  });
  
  d3.time.minutes = d3.time.minute.range;
  d3.time.minutes.utc = d3.time.minute.utc.range;
  d3.time.hour = d3_time_interval(function(date) {
    var timezone = date.getTimezoneOffset() / 60;
    return new d3_time((Math.floor(date / 36e5 - timezone) + timezone) * 36e5);
  }, function(date, offset) {
    date.setTime(date.getTime() + Math.floor(offset) * 36e5); // DST breaks setHours
  }, function(date) {
    return date.getHours();
  });
  
  d3.time.hours = d3.time.hour.range;
  d3.time.hours.utc = d3.time.hour.utc.range;
  d3.time.day = d3_time_interval(function(date) {
    return new d3_time(date.getFullYear(), date.getMonth(), date.getDate());
  }, function(date, offset) {
    date.setDate(date.getDate() + offset);
  }, function(date) {
    return date.getDate() - 1;
  });
  
  d3.time.days = d3.time.day.range;
  d3.time.days.utc = d3.time.day.utc.range;
  
  d3.time.dayOfYear = function(date) {
    var year = d3.time.year(date);
    return Math.floor((date - year) / 864e5 - (date.getTimezoneOffset() - year.getTimezoneOffset()) / 1440);
  };
  d3_time_weekdays.forEach(function(day, i) {
    day = day.toLowerCase();
    i = 7 - i;
  
    var interval = d3.time[day] = d3_time_interval(function(date) {
      (date = d3.time.day(date)).setDate(date.getDate() - (date.getDay() + i) % 7);
      return date;
    }, function(date, offset) {
      date.setDate(date.getDate() + Math.floor(offset) * 7);
    }, function(date) {
      var day = d3.time.year(date).getDay();
      return Math.floor((d3.time.dayOfYear(date) + (day + i) % 7) / 7) - (day !== i);
    });
  
    d3.time[day + "s"] = interval.range;
    d3.time[day + "s"].utc = interval.utc.range;
  
    d3.time[day + "OfYear"] = function(date) {
      var day = d3.time.year(date).getDay();
      return Math.floor((d3.time.dayOfYear(date) + (day + i) % 7) / 7);
    };
  });
  
  d3.time.week = d3.time.sunday;
  d3.time.weeks = d3.time.sunday.range;
  d3.time.weeks.utc = d3.time.sunday.utc.range;
  d3.time.weekOfYear = d3.time.sundayOfYear;
  d3.time.month = d3_time_interval(function(date) {
    return new d3_time(date.getFullYear(), date.getMonth(), 1);
  }, function(date, offset) {
    date.setMonth(date.getMonth() + offset);
  }, function(date) {
    return date.getMonth();
  });
  
  d3.time.months = d3.time.month.range;
  d3.time.months.utc = d3.time.month.utc.range;
  d3.time.year = d3_time_interval(function(date) {
    return new d3_time(date.getFullYear(), 0, 1);
  }, function(date, offset) {
    date.setFullYear(date.getFullYear() + offset);
  }, function(date) {
    return date.getFullYear();
  });
  
  d3.time.years = d3.time.year.range;
  d3.time.years.utc = d3.time.year.utc.range;
  function d3_time_scale(linear, methods, format) {
  
    function scale(x) {
      return linear(x);
    }
  
    scale.invert = function(x) {
      return d3_time_scaleDate(linear.invert(x));
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return linear.domain().map(d3_time_scaleDate);
      linear.domain(x);
      return scale;
    };
  
    scale.nice = function(m) {
      var extent = d3_time_scaleExtent(scale.domain());
      return scale.domain([m.floor(extent[0]), m.ceil(extent[1])]);
    };
  
    scale.ticks = function(m, k) {
      var extent = d3_time_scaleExtent(scale.domain());
      if (typeof m !== "function") {
        var span = extent[1] - extent[0],
            target = span / m,
            i = d3.bisect(d3_time_scaleSteps, target);
        if (i == d3_time_scaleSteps.length) return methods.year(extent, m);
        if (!i) return linear.ticks(m).map(d3_time_scaleDate);
        if (Math.log(target / d3_time_scaleSteps[i - 1]) < Math.log(d3_time_scaleSteps[i] / target)) --i;
        m = methods[i];
        k = m[1];
        m = m[0].range;
      }
      return m(extent[0], new Date(+extent[1] + 1), k); // inclusive upper bound
    };
  
    scale.tickFormat = function() {
      return format;
    };
  
    scale.copy = function() {
      return d3_time_scale(linear.copy(), methods, format);
    };
  
    // TOOD expose d3_scale_linear_rebind?
    return d3.rebind(scale, linear, "range", "rangeRound", "interpolate", "clamp");
  }
  
  // TODO expose d3_scaleExtent?
  function d3_time_scaleExtent(domain) {
    var start = domain[0], stop = domain[domain.length - 1];
    return start < stop ? [start, stop] : [stop, start];
  }
  
  function d3_time_scaleDate(t) {
    return new Date(t);
  }
  
  function d3_time_scaleFormat(formats) {
    return function(date) {
      var i = formats.length - 1, f = formats[i];
      while (!f[1](date)) f = formats[--i];
      return f[0](date);
    };
  }
  
  function d3_time_scaleSetYear(y) {
    var d = new Date(y, 0, 1);
    d.setFullYear(y); // Y2K fail
    return d;
  }
  
  function d3_time_scaleGetYear(d) {
    var y = d.getFullYear(),
        d0 = d3_time_scaleSetYear(y),
        d1 = d3_time_scaleSetYear(y + 1);
    return y + (d - d0) / (d1 - d0);
  }
  
  var d3_time_scaleSteps = [
    1e3,    // 1-second
    5e3,    // 5-second
    15e3,   // 15-second
    3e4,    // 30-second
    6e4,    // 1-minute
    3e5,    // 5-minute
    9e5,    // 15-minute
    18e5,   // 30-minute
    36e5,   // 1-hour
    108e5,  // 3-hour
    216e5,  // 6-hour
    432e5,  // 12-hour
    864e5,  // 1-day
    1728e5, // 2-day
    6048e5, // 1-week
    2592e6, // 1-month
    7776e6, // 3-month
    31536e6 // 1-year
  ];
  
  var d3_time_scaleLocalMethods = [
    [d3.time.second, 1],
    [d3.time.second, 5],
    [d3.time.second, 15],
    [d3.time.second, 30],
    [d3.time.minute, 1],
    [d3.time.minute, 5],
    [d3.time.minute, 15],
    [d3.time.minute, 30],
    [d3.time.hour, 1],
    [d3.time.hour, 3],
    [d3.time.hour, 6],
    [d3.time.hour, 12],
    [d3.time.day, 1],
    [d3.time.day, 2],
    [d3.time.week, 1],
    [d3.time.month, 1],
    [d3.time.month, 3],
    [d3.time.year, 1]
  ];
  
  var d3_time_scaleLocalFormats = [
    [d3.time.format("%Y"), function(d) { return true; }],
    [d3.time.format("%B"), function(d) { return d.getMonth(); }],
    [d3.time.format("%b %d"), function(d) { return d.getDate() != 1; }],
    [d3.time.format("%a %d"), function(d) { return d.getDay() && d.getDate() != 1; }],
    [d3.time.format("%I %p"), function(d) { return d.getHours(); }],
    [d3.time.format("%I:%M"), function(d) { return d.getMinutes(); }],
    [d3.time.format(":%S"), function(d) { return d.getSeconds(); }],
    [d3.time.format(".%L"), function(d) { return d.getMilliseconds(); }]
  ];
  
  var d3_time_scaleLinear = d3.scale.linear(),
      d3_time_scaleLocalFormat = d3_time_scaleFormat(d3_time_scaleLocalFormats);
  
  d3_time_scaleLocalMethods.year = function(extent, m) {
    return d3_time_scaleLinear.domain(extent.map(d3_time_scaleGetYear)).ticks(m).map(d3_time_scaleSetYear);
  };
  
  d3.time.scale = function() {
    return d3_time_scale(d3.scale.linear(), d3_time_scaleLocalMethods, d3_time_scaleLocalFormat);
  };
  var d3_time_scaleUTCMethods = d3_time_scaleLocalMethods.map(function(m) {
    return [m[0].utc, m[1]];
  });
  
  var d3_time_scaleUTCFormats = [
    [d3.time.format.utc("%Y"), function(d) { return true; }],
    [d3.time.format.utc("%B"), function(d) { return d.getUTCMonth(); }],
    [d3.time.format.utc("%b %d"), function(d) { return d.getUTCDate() != 1; }],
    [d3.time.format.utc("%a %d"), function(d) { return d.getUTCDay() && d.getUTCDate() != 1; }],
    [d3.time.format.utc("%I %p"), function(d) { return d.getUTCHours(); }],
    [d3.time.format.utc("%I:%M"), function(d) { return d.getUTCMinutes(); }],
    [d3.time.format.utc(":%S"), function(d) { return d.getUTCSeconds(); }],
    [d3.time.format.utc(".%L"), function(d) { return d.getUTCMilliseconds(); }]
  ];
  
  var d3_time_scaleUTCFormat = d3_time_scaleFormat(d3_time_scaleUTCFormats);
  
  function d3_time_scaleUTCSetYear(y) {
    var d = new Date(Date.UTC(y, 0, 1));
    d.setUTCFullYear(y); // Y2K fail
    return d;
  }
  
  function d3_time_scaleUTCGetYear(d) {
    var y = d.getUTCFullYear(),
        d0 = d3_time_scaleUTCSetYear(y),
        d1 = d3_time_scaleUTCSetYear(y + 1);
    return y + (d - d0) / (d1 - d0);
  }
  
  d3_time_scaleUTCMethods.year = function(extent, m) {
    return d3_time_scaleLinear.domain(extent.map(d3_time_scaleUTCGetYear)).ticks(m).map(d3_time_scaleUTCSetYear);
  };
  
  d3.time.scale.utc = function() {
    return d3_time_scale(d3.scale.linear(), d3_time_scaleUTCMethods, d3_time_scaleUTCFormat);
  };
  })();