Merge pull request #3619 from dieterv77/FixGH3601

BUG: (GH3601) Reindex data if reordering time/period index

Author: dieterv77

RELEASE.rst

@@ -127,6 +127,7 @@ pandas 0.11.1
     when ``parse_dates`` is specified (GH3062_)
   - Fix not consolidating before to_csv (GH3624_)
   - Fix alignment issue when setitem in a DataFrame with a piece of a DataFrame (GH3626_)
+  - Fix plotting of unordered DatetimeIndex (GH3601_)
 
 .. _GH3164: https://github.com/pydata/pandas/issues/3164
 .. _GH2786: https://github.com/pydata/pandas/issues/2786
@@ -180,6 +181,7 @@ pandas 0.11.1
 .. _GH3062: https://github.com/pydata/pandas/issues/3062
 .. _GH3624: https://github.com/pydata/pandas/issues/3624
 .. _GH3626: https://github.com/pydata/pandas/issues/3626
+.. _GH3601: https://github.com/pydata/pandas/issues/3601
 .. _GH1512: https://github.com/pydata/pandas/issues/1512
 
 

pandas/tests/test_graphics.py

@@ -677,14 +677,16 @@ def test_default_color_cycle(self):
 
     @slow
     def test_unordered_ts(self):
-        df = DataFrame(np.random.randn(3, 1),
+        df = DataFrame(np.array([3.0, 2.0, 1.0]),
                        index=[date(2012, 10, 1),
                               date(2012, 9, 1),
                               date(2012, 8, 1)],
                        columns=['test'])
         ax = df.plot()
         xticks = ax.lines[0].get_xdata()
         self.assert_(xticks[0] < xticks[1])
+        ydata = ax.lines[0].get_ydata()
+        self.assert_(np.all(ydata == np.array([1.0, 2.0, 3.0])))
 
 class TestDataFrameGroupByPlots(unittest.TestCase):
 

pandas/tools/plotting.py

@@ -947,8 +947,8 @@ def _get_xticks(self, convert_period=False):
 
         if self.use_index:
             if convert_period and isinstance(index, PeriodIndex):
-                index = index.to_timestamp().order()
-                x = index._mpl_repr()
+                self.data = self.data.reindex(index=index.order())
+                x = self.data.index.to_timestamp()._mpl_repr()
             elif index.is_numeric():
                 """
                 Matplotlib supports numeric values or datetime objects as
@@ -958,7 +958,8 @@ def _get_xticks(self, convert_period=False):
                 """
                 x = index._mpl_repr()
             elif is_datetype:
-                x = index.order()._mpl_repr()
+                self.data = self.data.reindex(index=index.order())
+                x = self.data.index._mpl_repr()
             else:
                 self._need_to_set_index = True
                 x = range(len(index))