Suppress sharing warnings when no sharing is possible

ultraplot/axes/base.py

@@ -1347,22 +1347,24 @@ def shared(paxs):
 
         # External axes sharing, sometimes overrides panel axes sharing
         # Share x axes within compatible groups
-        axes_x = self._get_share_axes("x")
-        for group in self.figure._partition_share_axes(axes_x, "x"):
-            if not group:
-                continue
-            parent, *children = group
-            for child in children:
-                child._sharex_setup(parent)
+        if self.figure._sharex > 0:
+            axes_x = self._get_share_axes("x")
+            for group in self.figure._partition_share_axes(axes_x, "x"):
+                if not group:
+                    continue
+                parent, *children = group
+                for child in children:
+                    child._sharex_setup(parent)
 
         # Share y axes within compatible groups
-        axes_y = self._get_share_axes("y")
-        for group in self.figure._partition_share_axes(axes_y, "y"):
-            if not group:
-                continue
-            parent, *children = group
-            for child in children:
-                child._sharey_setup(parent)
+        if self.figure._sharey > 0:
+            axes_y = self._get_share_axes("y")
+            for group in self.figure._partition_share_axes(axes_y, "y"):
+                if not group:
+                    continue
+                parent, *children = group
+                for child in children:
+                    child._sharey_setup(parent)
 
         # Global sharing, use the reference subplot where compatible
         ref = self.figure._subplot_dict.get(self.figure._refnum, None)

ultraplot/figure.py

@@ -1325,6 +1325,15 @@ def _share_ticklabels(self, *, axis: str) -> None:
 
         # Process each group independently
         for _, group_axes in groups.items():
+            # Nothing to share if the group is too small or sharing is disabled —
+            # avoids unsupported-type warnings (e.g. PolarAxes) for those cases.
+            if len(group_axes) < 2:
+                continue
+            if all(
+                self._effective_share_level(axi, axis, sides) < 3 for axi in group_axes
+            ):
+                continue
+
             # Build baseline from MAIN axes only (exclude panels)
             baseline, skip_group = self._compute_baseline_tick_state(
                 group_axes, axis, label_keys

ultraplot/tests/test_figure.py

@@ -354,6 +354,56 @@ def test_explicit_share_warns_for_mixed_cartesian_polar():
     assert len(incompatible) == 1
 
 
+def test_share_zero_polar_emits_no_warnings(recwarn):
+    fig, axs = uplt.subplots(proj="polar", ncols=2, nrows=3, share=0)
+    fig.canvas.draw()
+
+    ultra = [
+        w
+        for w in recwarn
+        if issubclass(w.category, uplt.internals.warnings.UltraPlotWarning)
+    ]
+    assert ultra == [], [str(w.message) for w in ultra]
+
+
+def test_share_zero_mixed_cartesian_polar_emits_no_warnings(recwarn):
+    fig, axs = uplt.subplots(ncols=2, proj=("cart", "polar"), share=0)
+    fig.canvas.draw()
+
+    ultra = [
+        w
+        for w in recwarn
+        if issubclass(w.category, uplt.internals.warnings.UltraPlotWarning)
+    ]
+    assert ultra == [], [str(w.message) for w in ultra]
+
+
+def test_share_default_single_polar_emits_no_warnings(recwarn):
+    """A single polar axis has nothing to share — must not warn at default share."""
+    fig, ax = uplt.subplots(proj="polar")
+    fig.canvas.draw()
+
+    ultra = [
+        w
+        for w in recwarn
+        if issubclass(w.category, uplt.internals.warnings.UltraPlotWarning)
+    ]
+    assert ultra == [], [str(w.message) for w in ultra]
+
+
+def test_share_default_single_polar_subplot_singular_emits_no_warnings(recwarn):
+    """``uplt.subplot(proj='polar')`` (singular) has nothing to share either."""
+    fig, ax = uplt.subplot(proj="polar")
+    fig.canvas.draw()
+
+    ultra = [
+        w
+        for w in recwarn
+        if issubclass(w.category, uplt.internals.warnings.UltraPlotWarning)
+    ]
+    assert ultra == [], [str(w.message) for w in ultra]
+
+
 def test_auto_share_local_yscale_change_splits_group():
     fig, axs = uplt.subplots(ncols=2, share="auto")
     fig.canvas.draw()