BUG: Cast ExtensionArray to numpy ndarray before plot (pandas-dev#25590)

* Cast `ExtensionArray` to `nd.array` before plot.

doc/source/whatsnew/v0.25.0.rst

@@ -225,6 +225,7 @@ I/O
 Plotting
 ^^^^^^^^
 
+- Fixed bug where :class:`api.extensions.ExtensionArray` could not be used in matplotlib plotting (:issue:`25587`)
 -
 -
 -

pandas/plotting/_core.py

@@ -365,6 +365,12 @@ def _compute_plot_data(self):
         if is_empty:
             raise TypeError('no numeric data to plot')
 
+        # GH25587: cast ExtensionArray of pandas (IntegerArray, etc.) to
+        # np.ndarray before plot.
+        numeric_data = numeric_data.copy()
+        for col in numeric_data:
+            numeric_data[col] = np.asarray(numeric_data[col])
+
         self.data = numeric_data
 
     def _make_plot(self):
@@ -1794,7 +1800,6 @@ def _plot(data, x=None, y=None, subplots=False,
                         )
                     label_name = label_kw or data.columns
                     data.columns = label_name
-
         plot_obj = klass(data, subplots=subplots, ax=ax, kind=kind, **kwds)
 
     plot_obj.generate()

pandas/tests/plotting/test_frame.py

@@ -18,6 +18,7 @@
 import pandas as pd
 from pandas import (
     DataFrame, MultiIndex, PeriodIndex, Series, bdate_range, date_range)
+from pandas.core.arrays import integer_array
 from pandas.tests.plotting.common import (
     TestPlotBase, _check_plot_works, _ok_for_gaussian_kde,
     _skip_if_no_scipy_gaussian_kde)
@@ -144,8 +145,26 @@ def test_plot(self):
         result = ax.axes
         assert result is axes[0]
 
-    # GH 15516
+    def test_integer_array_plot(self):
+        # GH 25587
+        arr = integer_array([1, 2, 3, 4], dtype="UInt32")
+
+        s = Series(arr)
+        _check_plot_works(s.plot.line)
+        _check_plot_works(s.plot.bar)
+        _check_plot_works(s.plot.hist)
+        _check_plot_works(s.plot.pie)
+
+        df = DataFrame({'x': arr, 'y': arr})
+        _check_plot_works(df.plot.line)
+        _check_plot_works(df.plot.bar)
+        _check_plot_works(df.plot.hist)
+        _check_plot_works(df.plot.pie, y='y')
+        _check_plot_works(df.plot.scatter, x='x', y='y')
+        _check_plot_works(df.plot.hexbin, x='x', y='y')
+
     def test_mpl2_color_cycle_str(self):
+        # GH 15516
         colors = ['C' + str(x) for x in range(10)]
         df = DataFrame(randn(10, 3), columns=['a', 'b', 'c'])
         for c in colors: