PERF: Defer tick materialization during Axes init/clear#31525
Conversation
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
5708dc8 to
3ac8224
Compare
timhoffm
left a comment
There was a problem hiding this comment.
Thanks for the PR. The speedup is impressive, and the added complexity (rc caching) is bearable.
Strategically, I would like to move away from single-tick handling, but in the mean time this is a reasonable improvement.
Having tick collections is indeed the way to go. This change is orthogonal as it avoids some tick operations altogether. (but maybe if ticks are really fast that would not matter) |
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>
a3f1be1 to
d0ed04c
Compare
timhoffm
left a comment
There was a problem hiding this comment.
Thanks, this is a substantial and concise improvement now!
Thanks for reviews! This was (and still is) tricky to get right. If you have more suggestions (in particular for additional tests) let me know |
|
I think this causes an issue for cartopy (SciTools/cartopy#2674) |
|
@mathause Thanks for reporting. I have a branch with a potential fix (unverified yet). Could you check whether that works? main...eendebakpt:matplotlib:fix/clear-custom-spine-type |
|
[Picking up my Cartopy hat] Thanks for catching that @mathause and for the quick fix @eendebakpt. I confirm I reproduced the error in the Cartopy tests, and that the tests pass with the new branch. |
PR #31525 made Axes.__clear call Spine._ensure_transform_is_set on every spine, which calls set_position(('outward', 0.0)) for a spine that still carries the placeholder transform from Spine.__init__. Custom spines such as cartopy's GeoSpine have a non-cartesian spine_type, manage their own transform, and may reject set_position, so this raised NotImplementedError on plain subplot creation. Restrict the spine nudge to the four standard cartesian spine types, the only ones set_position / get_spine_transform support. See SciTools/cartopy#2674. Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

PR summary
The performance if matplotlibs ticks is a bottleneck in various plots. See for example the discussions and references in #5665, #31012, #29594.
In this PR we prevent materialization of the
_LazyTickListwhen there are no ticks created yet. With the tick-materialization cascade gone from Axes.__clear, the spine transforms the cascade used to install as a side effect are installed explicitly at the end of __clear.Benchmark results (updated):
Benchmark script
Closes #23771.
AI Disclosure
Claude was used in identifying performance bottlenecks related to tick creation. Initially the goal was to create tick collections (as described in one of the references), but this approach seems to be a small change with large impact.
PR checklist