René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[MNT]: deprecate \"which\" parameter of `Axes.set_position`?","articleBody":"### Summary\n\nAs a user, I was always confused by the *which* parameter of `set_position` and under what circumstance one might set the active position.  The [docstring](https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.set_position.html) indicates that the original and active positions are usually the same unless a fixed aspect ratio is set.\n\nLooking through the [code of apply_aspect](https://github.com/matplotlib/matplotlib/blob/829a9cc1da1ed99671eefc52df897f8b178aad91/lib/matplotlib/axes/_base.py#L1943), I think it always updates the active position.  Since `apply_aspect` gets called within `draw`, `get_tightbbox` and `get_position`, it's not clear to me that the user can ever effectively set the active position directly, unless they made an axes subclass that replaced `apply_aspect`.\n\n`apply_aspect` itself uses a private `_set_position` that was factored out of `set_position` at #9082.  So maybe the existence of the _which_ parameter in the public function is a hangover from before that and is no longer needed.\n\n### Proposed fix\n\nEither deprecate the _which_ parameter in the public method so it only sets the original position, or make it clear in the docstring that setting the active position will almost never be effective.","author":{"url":"https://github.com/rcomer","@type":"Person","name":"rcomer"},"datePublished":"2026-03-07T17:36:48.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/31254/matplotlib/issues/31254"}