Update lcf_graph docstring.

Use numpydoc docstring standard and fixup formatting/examples.

networkx/generators/small.py

@@ -64,36 +64,51 @@ def LCF_graph(n, shift_list, repeats, create_using=None):
     """
     Return the cubic graph specified in LCF notation.
 
-    LCF notation (LCF=Lederberg-Coxeter-Fruchte) is a compressed
+    LCF (Lederberg-Coxeter-Fruchte) notation[1]_ is a compressed
     notation used in the generation of various cubic Hamiltonian
-    graphs of high symmetry. See, for example, dodecahedral_graph,
-    desargues_graph, heawood_graph and pappus_graph below.
+    graphs of high symmetry. See, for example, `dodecahedral_graph`,
+    `desargues_graph`, `heawood_graph` and `pappus_graph`.
 
-    n (number of nodes)
-      The starting graph is the n-cycle with nodes 0,...,n-1.
-      (The null graph is returned if n < 0.)
+    For each node ``n_i``, cycling through the n-cycle a total of ``len(shift_list) * repeats``
+    with shift cycling through `shift_list` `repeat` s times connects ``n_i``
+    with ``n_i + shift mod n``.
 
-    shift_list = [s1,s2,..,sk], a list of integer shifts mod n,
+    Parameters
+    ----------
+    n : int
+       The starting graph is the `n`-cycle with nodes ``0, ..., n-1``.
+       The null graph is returned if `n` < 1.
 
-    repeats
-      integer specifying the number of times that shifts in shift_list
-      are successively applied to each v_current in the n-cycle
-      to generate an edge between v_current and v_current+shift mod n.
+    shift_list : list
+       A list of integer shifts mod `n`, ``[s1, s2, .., sk]``
 
-    For v1 cycling through the n-cycle a total of k*repeats
-    with shift cycling through shiftlist repeats times connect
-    v1 with v1+shift mod n
+    repeats : int
+       Integer specifying the number of times that shifts in `shift_list`
+       are successively applied to each current node in the n-cycle
+       to generate an edge between ``n_current`` and ``n_current + shift mod n``.
 
+    Returns
+    -------
+    G : Graph
+       A graph instance created from the specified LCF notation.
+
+    Examples
+    --------
     The utility graph $K_{3,3}$
 
     >>> G = nx.LCF_graph(6, [3, -3], 3)
+    >>> G.edges()
+    EdgeView([(0, 1), (0, 5), (0, 3), (1, 2), (1, 4), (2, 3), (2, 5), (3, 4), (4, 5)])
 
-    The Heawood graph
+    The Heawood graph:
 
     >>> G = nx.LCF_graph(14, [5, -5], 7)
+    >>> nx.is_isomorphic(G, nx.heawood_graph())
+    True
 
-    See http://mathworld.wolfram.com/LCFNotation.html for a description
-    and references.
+    References
+    ----------
+    .. [1] https://en.wikipedia.org/wiki/LCF_notation
 
     """
     if n <= 0: