FIX: Make tick dtype int for backwards compatibility

Author: nrebena

pandas/plotting/_matplotlib/core.py

@@ -1364,11 +1364,11 @@ def _make_plot(self):
 
             if self.orientation == "vertical":
                 ax.xaxis.update_units(self.ax_index)
-                self.tick_pos = ax.convert_xunits(self.ax_index)
+                self.tick_pos = ax.convert_xunits(self.ax_index).astype(np.int)
                 self.ax_pos = self.tick_pos - self.tickoffset
             elif self.orientation == "horizontal":
                 ax.yaxis.update_units(self.ax_index)
-                self.tick_pos = ax.convert_yunits(self.ax_index)
+                self.tick_pos = ax.convert_yunits(self.ax_index).astype(np.int)
                 self.ax_pos = self.tick_pos - self.tickoffset
 
             kwds = self.kwds.copy()

pandas/tests/plotting/test_frame.py

@@ -1130,18 +1130,14 @@ def test_bar_categorical(self):
         for df in [df1, df2]:
             ax = df.plot.bar()
             ticks = ax.xaxis.get_ticklocs()
-            tm.assert_numpy_array_equal(
-                ticks, np.array([0, 1, 2, 3, 4, 5], dtype=np.float)
-            )
+            tm.assert_numpy_array_equal(ticks, np.array([0, 1, 2, 3, 4, 5]))
             assert ax.get_xlim() == (-0.5, 5.5)
             # check left-edge of bars
             assert ax.patches[0].get_x() == -0.25
             assert ax.patches[-1].get_x() == 5.15
 
             ax = df.plot.bar(stacked=True)
-            tm.assert_numpy_array_equal(
-                ticks, np.array([0, 1, 2, 3, 4, 5], dtype=np.float)
-            )
+            tm.assert_numpy_array_equal(ticks, np.array([0, 1, 2, 3, 4, 5]))
             assert ax.get_xlim() == (-0.5, 5.5)
             assert ax.patches[0].get_x() == -0.25
             assert ax.patches[-1].get_x() == 4.75