ENH: allow passing a scale instance to set_scale

jklymak · jklymak · commit 90334bab48b6 · 2020-12-09T14:50:34.000-08:00
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -3510,7 +3510,7 @@ def set_xscale(self, value, **kwargs):
 
         Parameters
         ----------
-        value : {"linear", "log", "symlog", "logit", ...}
+        value : {"linear", "log", "symlog", "logit", ...} or `.ScaleBase`
             The axis scale type to apply.
 
         **kwargs
@@ -3836,7 +3836,7 @@ def set_yscale(self, value, **kwargs):
 
         Parameters
         ----------
-        value : {"linear", "log", "symlog", "logit", ...}
+        value : {"linear", "log", "symlog", "logit", ...} or `.ScaleBase`
             The axis scale type to apply.
 
         **kwargs
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -741,7 +741,10 @@ def get_scale(self):
         return self._scale.name
 
     def _set_scale(self, value, **kwargs):
-        self._scale = mscale.scale_factory(value, self, **kwargs)
+        if not isinstance(value, mscale.ScaleBase):
+            self._scale = mscale.scale_factory(value, self, **kwargs)
+        else:
+            self._scale = value
         self._scale.set_default_locators_and_formatters(self)
 
         self.isDefault_majloc = True
