Return minorticks as array, not as list.

The return type changed accidentally when remove_overlapping_locs was
introduced (except for NullLocator, which always returned a plain list).
Make the API consistent with majorticks, which are (mostly) always
returned as an array.

Modifying the test in test_colorbar is so-so, but that's the only place,
AFAICT, that currently tests anything with get_ticklocs(minor=True),
so...

Author: anntzer

lib/matplotlib/axis.py

@@ -1269,19 +1269,19 @@ def get_majorticklocs(self):
     def get_minorticklocs(self):
         """Return this Axis' minor tick locations in data coordinates."""
         # Remove minor ticks duplicating major ticks.
-        major_locs = self.major.locator()
-        minor_locs = self.minor.locator()
-        transform = self._scale.get_transform()
-        tr_minor_locs = transform.transform(minor_locs)
-        tr_major_locs = transform.transform(major_locs)
-        lo, hi = sorted(transform.transform(self.get_view_interval()))
-        # Use the transformed view limits as scale.  1e-5 is the default rtol
-        # for np.isclose.
-        tol = (hi - lo) * 1e-5
+        minor_locs = np.asarray(self.minor.locator())
         if self.remove_overlapping_locs:
-            minor_locs = [
-                loc for loc, tr_loc in zip(minor_locs, tr_minor_locs)
-                if ~np.isclose(tr_loc, tr_major_locs, atol=tol, rtol=0).any()]
+            major_locs = self.major.locator()
+            transform = self._scale.get_transform()
+            tr_minor_locs = transform.transform(minor_locs)
+            tr_major_locs = transform.transform(major_locs)
+            lo, hi = sorted(transform.transform(self.get_view_interval()))
+            # Use the transformed view limits as scale.  1e-5 is the default
+            # rtol for np.isclose.
+            tol = (hi - lo) * 1e-5
+            mask = np.isclose(tr_minor_locs[:, None], tr_major_locs[None, :],
+                              atol=tol, rtol=0).any(axis=1)
+            minor_locs = minor_locs[~mask]
         return minor_locs
 
     def get_ticklocs(self, *, minor=False):

lib/matplotlib/tests/test_colorbar.py

@@ -608,6 +608,7 @@ def test_colorbar_inverted_ticks():
     cbar.minorticks_on()
     ticks = cbar.get_ticks()
     minorticks = cbar.get_ticks(minor=True)
+    assert isinstance(minorticks, np.ndarray)
     cbar.ax.invert_yaxis()
     np.testing.assert_allclose(ticks, cbar.get_ticks())
     np.testing.assert_allclose(minorticks, cbar.get_ticks(minor=True))