BUG: error plotting inferred freq with N>1 #2116

Author: changhiskhan

pandas/tools/plotting.py

@@ -1025,6 +1025,7 @@ def _maybe_convert_index(self, data):
                 freq = getattr(data.index, 'inferred_freq', None)
             if isinstance(freq, DateOffset):
                 freq = freq.rule_code
+            freq = get_base_alias(freq)
             freq = get_period_alias(freq)
 
             if freq is None:

pandas/tseries/tests/test_plotting.py

@@ -65,6 +65,12 @@ def test_frame_inferred(self):
         df2.plot()
         plt.close('all')
 
+        # N > 1
+        idx = date_range('2008-1-1 00:15:00', freq='15T', periods=10)
+        idx = DatetimeIndex(idx.values, freq=None)
+        df = DataFrame(np.random.randn(len(idx), 3), index=idx)
+        df.plot()
+
     @slow
     def test_tsplot(self):
         from pandas.tseries.plotting import tsplot