Add support for minor ticks in 3d axes.

The actual implementation is shorter than deleting the copies of "Minor
ticks are not supported" in the various docstrings...

Author: anntzer

doc/users/next_whats_new/2019-06-25-AL.rst

@@ -0,0 +1,2 @@
+3D axes now support minor ticks
+```````````````````````````````

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -862,9 +862,6 @@ def set_zticks(self, *args, **kwargs):
         Set z-axis tick locations.
         See :meth:`matplotlib.axes.Axes.set_yticks` for more details.
 
-        .. note::
-            Minor ticks are not supported.
-
         .. versionadded:: 1.1.0
         """
         return self.zaxis.set_ticks(*args, **kwargs)
@@ -874,9 +871,6 @@ def get_zticks(self, minor=False):
         Return the z ticks as a list of locations
         See :meth:`matplotlib.axes.Axes.get_yticks` for more details.
 
-        .. note::
-            Minor ticks are not supported.
-
         .. versionadded:: 1.1.0
         """
         return self.zaxis.get_ticklocs(minor=minor)
@@ -894,10 +888,6 @@ def get_zminorticklabels(self):
         """
         Get the ztick labels as a list of Text instances
 
-        .. note::
-            Minor ticks are not supported. This function was added
-            only for completeness.
-
         .. versionadded :: 1.1.0
         """
         return cbook.silent_list('Text zticklabel',
@@ -908,9 +898,6 @@ def set_zticklabels(self, *args, **kwargs):
         Set z-axis tick labels.
         See :meth:`matplotlib.axes.Axes.set_yticklabels` for more details.
 
-        .. note::
-            Minor ticks are not supported by Axes3D objects.
-
         .. versionadded:: 1.1.0
         """
         return self.zaxis.set_ticklabels(*args, **kwargs)
@@ -920,9 +907,6 @@ def get_zticklabels(self, minor=False):
         Get ztick labels as a list of Text instances.
         See :meth:`matplotlib.axes.Axes.get_yticklabels` for more details.
 
-        .. note::
-            Minor ticks are not supported.
-
         .. versionadded:: 1.1.0
         """
         return cbook.silent_list('Text zticklabel',

lib/mpl_toolkits/mplot3d/axis3d.py

@@ -140,11 +140,17 @@ def get_tick_positions(self):
     def get_major_ticks(self, numticks=None):
         ticks = maxis.XAxis.get_major_ticks(self, numticks)
         for t in ticks:
-            t.tick1line.set_transform(self.axes.transData)
-            t.tick2line.set_transform(self.axes.transData)
-            t.gridline.set_transform(self.axes.transData)
-            t.label1.set_transform(self.axes.transData)
-            t.label2.set_transform(self.axes.transData)
+            for obj in [
+                    t.tick1line, t.tick2line, t.gridline, t.label1, t.label2]:
+                obj.set_transform(self.axes.transData)
+        return ticks
+
+    def get_minor_ticks(self, numticks=None):
+        ticks = maxis.XAxis.get_minor_ticks(self, numticks)
+        for t in ticks:
+            for obj in [
+                    t.tick1line, t.tick2line, t.gridline, t.label1, t.label2]:
+                obj.set_transform(self.axes.transData)
         return ticks
 
     def set_pane_pos(self, xys):

lib/mpl_toolkits/tests/baseline_images/test_mplot3d/minor_ticks.png

@@ -903,3 +903,14 @@ def test_ax3d_tickcolour():
         assert tick.tick1line._color == 'red'
     for tick in ax.zaxis.get_major_ticks():
         assert tick.tick1line._color == 'red'
+
+
+@image_comparison(["minor_ticks.png"], style="default")
+def test_minor_ticks():
+    ax = plt.figure().add_subplot(projection="3d")
+    ax.set_xticks([0.25], minor=True)
+    ax.set_xticklabels(["quarter"], minor=True)
+    ax.set_yticks([0.33], minor=True)
+    ax.set_yticklabels(["third"], minor=True)
+    ax.set_zticks([0.50], minor=True)
+    ax.set_zticklabels(["half"], minor=True)