René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"_make_norm_from_scale needs to process values","articleBody":"As noted in #18653, norms created via `colors._make_norm_from_scale` do not process values that are passed to `inverse` so `norm.inverse([0.2, 5, 10])` fails, whereas `norm.inverse(np.array([0.2, 5, 10]))` works fine.  \r\n\r\n@QuLogic noticed this: \r\n\r\nProbably because `inverse` doesn't pass `value` through `process_value` like `__call__` does. Something like:\r\n```diff\r\ndiff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py\r\nindex e417b8178d..b37ec947fa 100644\r\n--- a/lib/matplotlib/colors.py\r\n+++ b/lib/matplotlib/colors.py\r\n@@ -1449,12 +1449,14 @@ def _make_norm_from_scale(scale_cls, base_norm_cls=None, *, init=None):\r\n             t_vmin, t_vmax = self._trf.transform([self.vmin, self.vmax])\r\n             if not np.isfinite([t_vmin, t_vmax]).all():\r\n                 raise ValueError(\"Invalid vmin or vmax\")\r\n+            value, is_scalar = self.process_value(value)\r\n             rescaled = value * (t_vmax - t_vmin)\r\n             rescaled += t_vmin\r\n-            return (self._trf\r\n-                    .inverted()\r\n-                    .transform(rescaled)\r\n-                    .reshape(np.shape(value)))\r\n+            t_value = (self._trf\r\n+                       .inverted()\r\n+                       .transform(rescaled)\r\n+                       .reshape(np.shape(value)))\r\n+            return t_value[0] if is_scalar else t_value\r\n \r\n     Norm.__name__ = base_norm_cls.__name__\r\n     Norm.__qualname__ = base_norm_cls.__qualname__\r\n```\r\nMaybe it also needs the masking?\r\n\r\n_Originally posted by @QuLogic in https://github.com/matplotlib/matplotlib/pull/18653#discussion_r551657752_\r\n\r\n\r\n\r\n\r\n","author":{"url":"https://github.com/jklymak","@type":"Person","name":"jklymak"},"datePublished":"2021-01-05T01:33:25.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/19239/matplotlib/issues/19239"}