Fix bug in SymmetricalLogTransform.

efiring · efiring · commit d3ca16c154d0 · 2019-05-21T09:54:50.000-10:00
By failing the copy the input array, SymmetricalLogTransform.transform_non_affine was returning an array with points in the linear range masked. Closes #14265. Replaces #14281.
diff --git a/lib/matplotlib/scale.py b/lib/matplotlib/scale.py
@@ -489,7 +489,7 @@ def transform_non_affine(self, a):
         masked = ma.masked_inside(a,
                                   -self.linthresh,
                                   self.linthresh,
-                                  copy=False)
+                                  copy=True)
         log = sign * self.linthresh * (
             self._linscale_adj +
             ma.log(np.abs(masked) / self.linthresh) / self._log_base)
@@ -521,7 +521,7 @@ def __init__(self, base, linthresh, linscale):
     def transform_non_affine(self, a):
         sign = np.sign(a)
         masked = ma.masked_inside(a, -self.invlinthresh,
-                                  self.invlinthresh, copy=False)
+                                  self.invlinthresh, copy=True)
         exp = sign * self.linthresh * (
             ma.power(self.base, (sign * (masked / self.linthresh))
             - self._linscale_adj))
