Don't hide shared "x/y"ticklabels for grids of non-rectilinear axes.

anntzer · anntzer · commit 4c03610d18e3 · 2021-04-16T22:19:20.000+02:00
In particular, hiding the "x/y" (i.e. theta/r) ticklabels doesn't make
sense for polar axes, and I'd guess likewise for most projections other
than the default rectilinear.  Try e.g.
`subplots(2, 2, subplot_kw=dict(projection="polar"), sharex=True, sharey=True)`.
diff --git a/lib/matplotlib/gridspec.py b/lib/matplotlib/gridspec.py
@@ -308,12 +308,13 @@ def subplots(self, *, sharex=False, sharey=False, squeeze=True,
                     self[row, col], **subplot_kw)
 
         # turn off redundant tick labeling
-        if sharex in ["col", "all"]:
-            for ax in axarr.flat:
-                ax._label_outer_xaxis()
-        if sharey in ["row", "all"]:
-            for ax in axarr.flat:
-                ax._label_outer_yaxis()
+        if all(ax.name == "rectilinear" for ax in axarr.flat):
+            if sharex in ["col", "all"]:
+                for ax in axarr.flat:
+                    ax._label_outer_xaxis()
+            if sharey in ["row", "all"]:
+                for ax in axarr.flat:
+                    ax._label_outer_yaxis()
 
         if squeeze:
             # Discarding unneeded dimensions that equal 1.  If we only have one
diff --git a/lib/matplotlib/tests/test_polar.py b/lib/matplotlib/tests/test_polar.py
@@ -348,3 +348,10 @@ def test_thetalim_valid_invalid():
     with pytest.raises(ValueError,
                        match='The angle range must be <= 360 degrees'):
         ax.set_thetalim(thetamin=800, thetamax=400)
+
+
+def test_shared_polar_keeps_ticklabels():
+    _, axs = plt.subplots(
+        2, 2, subplot_kw=dict(projection="polar"), sharex=True, sharey=True)
+    assert axs[0, 1].xaxis._major_tick_kw["label1On"]
+    assert axs[0, 1].yaxis._major_tick_kw["label1On"]
