Axis sharing fix

ultraplot/axes/cartesian.py

@@ -576,7 +576,7 @@ def _sharex_limits(self, sharex):
             if ax1.get_autoscalex_on() and not ax2.get_autoscalex_on():
                 ax1.set_xlim(ax2.get_xlim())  # non-default limits
         # Copy non-default locators and formatters
-        self.get_shared_x_axes().joined(self, sharex)  # share limit/scale changes
+        self.sharex(sharex)
         if sharex.xaxis.isDefault_majloc and not self.xaxis.isDefault_majloc:
             sharex.xaxis.set_major_locator(self.xaxis.get_major_locator())
         if sharex.xaxis.isDefault_minloc and not self.xaxis.isDefault_minloc:
@@ -598,7 +598,7 @@ def _sharey_limits(self, sharey):
                 ax1.set_yscale(ax2.get_yscale())
             if ax1.get_autoscaley_on() and not ax2.get_autoscaley_on():
                 ax1.set_ylim(ax2.get_ylim())
-        self.get_shared_y_axes().joined(self, sharey)  # share limit/scale changes
+        self.sharey(sharey)
         if sharey.yaxis.isDefault_majloc and not self.yaxis.isDefault_majloc:
             sharey.yaxis.set_major_locator(self.yaxis.get_major_locator())
         if sharey.yaxis.isDefault_minloc and not self.yaxis.isDefault_minloc:

ultraplot/axes/shared.py

@@ -10,6 +10,7 @@
 from ..internals import ic  # noqa: F401
 from ..internals import _pop_kwargs
 from ..utils import _fontsize_to_pt, _not_none, units
+from ..axes import Axes
 
 
 class _SharedAxes(object):
@@ -184,3 +185,40 @@ def _update_ticks(
         if kwtext_extra:
             for lab in obj.get_ticklabels():
                 lab.update(kwtext_extra)
+
+    # Override matplotlib defaults to handle multiple axis sharing
+    def sharex(self, other):
+        return self._share_axis(which="x", other=other)
+
+    def sharey(self, other):
+        self._share_axis(which="y", other=other)
+
+    # Ultraplot internal function to share axes
+    def _share_axis(self, which, other):
+        if not isinstance(other, Axes):
+            return TypeError(
+                f"Cannot share axes with {type(other).__name__}.\n"
+                f"Expected: ultraplot.base.Axes instance\n"
+                f"Received: {type(other).__name__}\n"
+                "Please provide a valid Axes instance to share with."
+            )
+
+        self._shared_axes[which].join(self, other)
+
+        # Get axis objects
+        this_axis = getattr(self, f"{which}axis")
+        other_axis = getattr(other, f"{which}axis")
+
+        # Set minor ticker
+        this_axis.minor = other_axis.minor
+
+        # Get and set limits
+        limits = getattr(other, f"get_{which}lim")()
+        set_lim = getattr(self, f"set_{which}lim")
+        get_autoscale = getattr(other, f"get_autoscale{which}_on")
+
+        lim0, lim1 = limits
+        set_lim(lim0, lim1, emit=False, auto=get_autoscale())
+
+        # Set scale
+        this_axis._scale = other_axis._scale

ultraplot/tests/test_1dplots.py

@@ -378,7 +378,6 @@ def test_scatter_sizes():
 from matplotlib import tri
 
 
-@pytest.mark.mpl_image_compare
 @pytest.mark.mpl_image_compare
 @pytest.mark.parametrize(
     "x, y, z, triangles, use_triangulation, use_datadict",

ultraplot/tests/test_subplots.py

@@ -172,3 +172,47 @@ def test_reference_aspect():
     fig.auto_layout()
     assert np.isclose(refwidth, axs[fig._refnum - 1]._get_size_inches()[0])
     return fig
+
+
+@pytest.mark.mpl_image_compare
+@pytest.mark.parametrize("share", ["limits", "labels"])
+def test_axis_sharing(share):
+    fig, ax = uplt.subplots(ncols=2, nrows=2, share=share, span=False)
+    labels = ["A", "B", "C", "D"]
+    for idx, axi in enumerate(ax):
+        axi.scatter(idx, idx)
+        axi.set_xlabel(labels[idx])
+        axi.set_ylabel(labels[idx])
+
+    # TODO: the labels are handled in a funky way. The plot looks fine but
+    # the label are not "shared" that is the labels still exist but they
+    # are not visible and instead there are new labels created. Need to
+    # figure this out.
+    # test left hand side
+    if share != "labels":
+        assert all([i == j for i, j in zip(ax[0].get_xlim(), ax[2].get_xlim())])
+        assert all([i == j for i, j in zip(ax[0].get_ylim(), ax[1].get_ylim())])
+        assert all([i == j for i, j in zip(ax[1].get_xlim(), ax[3].get_xlim())])
+    elif share == "labels":
+        ax.draw(
+            fig.canvas.get_renderer()
+        )  # forcing a draw to ensure the labels are shared
+        # columns shares x label; top row should be empty
+        assert ax[0].xaxis.get_label().get_visible() == False
+        assert ax[1].xaxis.get_label().get_visible() == False
+
+        assert ax[2].xaxis.get_label().get_visible() == True
+        assert ax[2].get_xlabel() == "A"
+        assert ax[3].xaxis.get_label().get_visible() == True
+        assert ax[3].get_xlabel() == "B"
+
+        # rows share ylabel
+        assert ax[3].yaxis.get_label().get_visible() == False
+        assert ax[1].yaxis.get_label().get_visible() == False
+
+        assert ax[0].yaxis.get_label().get_visible() == True
+        assert ax[2].yaxis.get_label().get_visible() == True
+        assert ax[0].get_ylabel() == "B"
+        assert ax[2].get_ylabel() == "D"
+
+    return fig