box aspect for axes

ImportanceOfBeingErnest · ImportanceOfBeingErnest · commit 25da9645f691 · 2019-07-30T03:07:49.000+02:00
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -426,6 +426,7 @@ def __init__(self, fig, rect,
         self.axes = self
         self._aspect = 'auto'
         self._adjustable = 'box'
+        self._box_aspect = None
         self._anchor = 'C'
         self._stale_viewlim_x = False
         self._stale_viewlim_y = False
@@ -1282,6 +1283,18 @@ def set_aspect(self, aspect, adjustable=None, anchor=None, share=False):
         self.stale = True
 
     def get_adjustable(self):
+        """
+        Returns the adjustable parameter, *{'box', 'datalim'}* that defines
+        which parameter the Axes will change to achieve a given aspect.
+
+        See Also
+        --------
+        matplotlib.axes.Axes.set_adjustable
+            defining the parameter to adjust in order to meet the required
+            aspect.
+        matplotlib.axes.Axes.set_aspect
+            for a description of aspect handling.
+        """
         return self._adjustable
 
     def set_adjustable(self, adjustable, share=False):
@@ -1333,6 +1346,29 @@ def set_adjustable(self, adjustable, share=False):
             ax._adjustable = adjustable
         self.stale = True
 
+    def get_box_aspect(self):
+        """
+        Get the axes box aspect.
+        Will be ``None`` if not explicitely specified.
+        """
+        return self._box_aspect
+
+    def set_box_aspect(self, aspect=None):
+        """ Set the axes box aspect. May be ``None`` or a number."""
+        axs = {*self._twinned_axes.get_siblings(self),
+               *self._twinned_axes.get_siblings(self)}
+
+        if aspect is not None:
+            aspect = float(aspect)
+            # when box_aspect is set to other than ´None`,
+            # adjustable must be "datalim"
+            for ax in axs:
+                ax.set_adjustable("datalim")
+
+        for ax in axs:
+            ax._box_aspect = aspect
+            ax.stale = True
+
     def get_anchor(self):
         """
         Get the anchor location.
@@ -1464,7 +1500,7 @@ def apply_aspect(self, position=None):
 
         aspect = self.get_aspect()
 
-        if aspect == 'auto':
+        if aspect == 'auto' and self._box_aspect is None:
             self._set_position(position, which='active')
             return
 
@@ -1484,11 +1520,20 @@ def apply_aspect(self, position=None):
             self._set_position(pb1.anchored(self.get_anchor(), pb), 'active')
             return
 
-        # self._adjustable == 'datalim'
+        # The following is only seen if self._adjustable == 'datalim'
+        if self._box_aspect is not None:
+            pb = position.frozen()
+            pb1 = pb.shrunk_to_aspect(self._box_aspect, pb, fig_aspect)
+            self._set_position(pb1.anchored(self.get_anchor(), pb), 'active')
+            if aspect == "auto":
+                return
 
         # reset active to original in case it had been changed by prior use
         # of 'box'
-        self._set_position(position, which='active')
+        if self._box_aspect is None:
+            self._set_position(position, which='active')
+        else:
+            position = pb1.anchored(self.get_anchor(), pb)
 
         x_trf = self.xaxis.get_transform()
         y_trf = self.yaxis.get_transform()
