BUG: fix log bar plot again #3309

closes #3309

Author: y-p

pandas/tests/test_graphics.py

@@ -409,16 +409,16 @@ def test_bar_log(self):
         # GH3254, GH3298 matplotlib/matplotlib#1882, #1892
         # regressions in 1.2.1
 
-        df = DataFrame({'A': [3] * 5, 'B': range(5)}, index=range(5))
+        df = DataFrame({'A': [3] * 5, 'B': range(1,6)}, index=range(5))
         ax = df.plot(kind='bar', grid=True,log=True)
         self.assertEqual(ax.yaxis.get_ticklocs()[0],1.0)
 
         p1 = Series([200,500]).plot(log=True,kind='bar')
         p2 = DataFrame([Series([200,300]),Series([300,500])]).plot(log=True,kind='bar',subplots=True)
 
         (p1.yaxis.get_ticklocs() == np.array([ 0.625,  1.625]))
-        (p2[0].yaxis.get_ticklocs() == np.array([ 100., 1000.])).all()
-        (p2[1].yaxis.get_ticklocs() == np.array([ 100., 1000.])).all()
+        (p2[0].yaxis.get_ticklocs() == np.array([ 1., 10., 100., 1000.])).all()
+        (p2[1].yaxis.get_ticklocs() == np.array([ 1., 10., 100., 1000.])).all()
 
     @slow
     def test_boxplot(self):

pandas/tools/plotting.py

@@ -1374,9 +1374,13 @@ def _make_plot(self):
             kwds = self.kwds.copy()
             kwds['color'] = colors[i % len(colors)]
 
-            # default, GH3254
-            # I tried, I really did.
-            start = 0 if mpl.__version__ == "1.2.1" else None
+            start =0
+            if self.log:
+                start = 1
+                if any(y < 1):
+                    # GH3254
+                    start = 0 if mpl.__version__ == "1.2.1" else None
+
             if self.subplots:
                 ax = self._get_ax(i)  # self.axes[i]