BUG: Correct KeyError from matplotlib when processing Series yerr

closes #11858

Author: Gábor Lipták <gliptak@gmail.com>

Closes #13114 from gliptak/yerr1 and squashes the following commits:

926329a [Gábor Lipták] Correct KeyError from matplotlib when processing Series xerr/yerr

codecov.yml

@@ -7,7 +7,3 @@ coverage:
       default:
         target: '50'
         branches: null
-    changes:
-      default:
-        branches:
-          - master

doc/source/whatsnew/v0.18.2.txt

@@ -33,7 +33,6 @@ Other enhancements
 
 
 
-
 .. _whatsnew_0182.api:
 
 API changes
@@ -108,6 +107,7 @@ Performance Improvements
 Bug Fixes
 ~~~~~~~~~
 - Bug in ``SparseDataFrame`` in which ``axis=None`` did not default to ``axis=0`` (:issue:`13048`)
+- Bug when passing a not-default-indexed ``Series`` as ``xerr`` or ``yerr`` in ``.plot()`` (:issue:`11858`)
 
 
 

pandas/tools/plotting.py

@@ -1331,6 +1331,10 @@ class MPLPlot(object):
             x = x._mpl_repr()
 
         if is_errorbar:
+            if 'xerr' in kwds:
+                kwds['xerr'] = np.array(kwds.get('xerr'))
+            if 'yerr' in kwds:
+                kwds['yerr'] = np.array(kwds.get('yerr'))
             return ax.errorbar(x, y, **kwds)
         else:
             # prevent style kwarg from going to errorbar, where it is

pandas/tseries/tests/test_plotting.py

@@ -76,6 +76,13 @@ class TestTSPlot(tm.TestCase):
         df = DataFrame(np.random.randn(len(idx), 3), index=idx)
         _check_plot_works(df.plot)
 
+    def test_is_error_nozeroindex(self):
+        # GH11858
+        i = np.array([1, 2, 3])
+        a = DataFrame(i, index=i)
+        _check_plot_works(a.plot, xerr=a)
+        _check_plot_works(a.plot, yerr=a)
+
     def test_nonnumeric_exclude(self):
         import matplotlib.pyplot as plt