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Add zoom_factory to matplotlib - where to put? #18159
Description
@tacaswell wrote a zoom_factory function that enables zooming with the mouse scroll wheel in this gist: https://gist.github.com/tacaswell/3144287 this is very useful and would be great if it was offered as a utility function by matplotlib. In mpl-extensions/mpl-interactions#21 (comment) tacaswell wrote:
I am 👍 on a PR to core Matplotlib to add that factory (not sure where) as it is useful in all backends (not just ipympl).
So this issue is to discuss whether/where to incorporate the zoom_factory function. Two initial suggestions:
- in the toolbar
- in pyplot
- Architecturally I don't think this makes as much sense but as a user I don't think I would expect to look at the toolbar for utility methods
Additionally I forked that gist (https://gist.github.com/ianhi/b638e09fa7a00764ea539940a0519af9) and added two things:
- push initial position to toolbar navstack so the home button works as expected
- automatic centering when zoomed out past initial bounds
- This could be made optional
if this were to be incorporated in matplotlib it would be nice to have those features as well.
Here is a gif of this with with some extra code to allow middle click to pan(https://gist.github.com/ianhi/5f514c31f13cc28fbd167849867122b7):
Activity
tacaswell commentedon Aug 3, 2020
It should not go in pyplot as we want this available to people who avoid the global state tracking of pyplot.
This should probably go in https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/backend_tools.py and target the MEP22 style toolbars. I suspect that we would want to have this enabled by default on the zoom tool?
ianhi commentedon Aug 3, 2020
Do you mean on
zoom to rect? I think that adding this to the panning mode feels the most natural:though it will be good to keep this available outside of a toolbar button to allow greater control. For instance I use this with middle click to pan and left click to use the lasso tool.
ianhi commentedon Jun 17, 2021
This would be fixed by #20317
github-actions commentedon Mar 16, 2026
This issue has been marked "inactive" because it has been 365 days since the last comment. If this issue is still present in recent Matplotlib releases, or the feature request is still wanted, please leave a comment and this label will be removed. If there are no updates in another 30 days, this issue will be automatically closed, but you are free to re-open or create a new issue if needed. We value issue reports, and this procedure is meant to help us resurface and prioritize issues that have not been addressed yet, not make them disappear. Thanks for your help!
timhoffm commentedon Mar 16, 2026
Fixed by #30405.