NotificationsYou must be signed in to change notification settings
Fork2.8k
Star18.1k

Allow`shared_yaxes` to work with secondary axes#5180

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to ourterms of service andprivacy statement. We’ll occasionally send you account related emails.

Already on GitHub?Sign in to your account

Jump to bottom

Merged

emilykl merged 10 commits intoplotly:mainfromgmjw:secondary-y-shared

Oct 1, 2025

Merged

Allow`shared_yaxes` to work with secondary axes#5180

emilykl merged 10 commits intoplotly:mainfromgmjw:secondary-y-shared

Oct 1, 2025

Conversation

Copy link

Contributor

gmjw commentedMay 12, 2025•
edited
Loading

I have read through thecontributing notes and understand the structure of the package. In particular, if my PR modifies code of plotly.graph_objects, my modifications concern the codegen files and not generated files.
I have added tests (if submitting a new feature or correcting a bug) or modified existing tests.
For a new feature, I have added documentation examples in an existing or new tutorial notebook (please see the doc checklist as well).
I have added a CHANGELOG entry if fixing/changing/adding anything substantial.
For a new feature or a change in behaviour, I have updated the relevant docstrings in the code to describe the feature or behaviour (please see the doc checklist as well).

Theshared_yaxes parameter to make_subplots did not previously work onsecondary y-axes. It had no effect.

This PR fixes this, without affecting how the parameter is applied to normal plots (without secondary y-axes). I have added a simple test to show how the new code "matches" secondary y-axes. The sharing for secondary y-axes is applied right-to-left, in the same way that the sharing for primary y-axes is applied left-to-right (I believe this results in the clearest separation of tick marks when viewing the final plot).

I believe this is a bugfix/improvement. I'm not sure if it's a new feature worthy of any documentation.

I will add some images showing a before/after comparison in comments.

Gareth Williams added4 commits

May 12, 2025 21:12

Fix sharing of secondary y-axis

fd64e00

Add test

8f0ac47

black

948bc38

black

dcc607c

Copy link

ContributorAuthor

gmjw commentedMay 12, 2025•
edited
Loading

This is the output of the test adjusted in the PR, withshared_yaxes=True, before and after the changes. You can see that after the changes the secondary y-axes are shared across rows, whereas previously only primary y-axes were shared.

Copy link

ContributorAuthor

gmjw commentedMay 12, 2025

This is my first PR to this repo, I've done my best but please let me know if there's anything I've forgotten or that could be done better.

In particular I'm not sure if/how I should add to the CHANGELOG file.

gmjw commented

May 12, 2025

View reviewed changes

tests/test_core/test_subplots/test_make_subplots.py

		[{"secondary_y":True}, {"secondary_y":True}],
		],
		)
		forshared_y_axesin [False,True]:

Copy link

ContributorAuthor

gmjwMay 12, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others.Learn more.

Ideally I would have passed in these options usingmark.parametrize, but I don't think that is possible with unittest TestCase methods.

gvwilson requested a review frommarthacryan

May 20, 2025 14:05

gvwilson self-assigned this

May 20, 2025

gvwilson added feature

something new

considered for next cycle

communitycommunity contribution labels

May 20, 2025

Copy link

Contributor

gvwilson commentedMay 20, 2025

thanks@gmjw - I'll try to get this merged in for the 6.2 release.

Copy link

ContributorAuthor

gmjw commentedJun 25, 2025

Thanks@gvwilson - just checking in to see if this could be merged soon - thanks!

gvwilson requested review fromemilykl andgvwilson and removed request formarthacryan

June 26, 2025 12:39

Merge branch 'main' into secondary-y-shared

7fd2702

emilykl reviewed

Jun 27, 2025

View reviewed changes

plotly/_subplots.py Outdated

Comment on lines 751 to 754

		ifsecondary_y:
		_configure_shared_axes(
		layout,grid_ref,specs,"y",shared_yaxes,row_dir,True
		)

Copy link

Contributor

emilyklJun 27, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others.Learn more.

@gmjw I think there's a logic issue here --secondary_y is set in the loop above, which loops through all thespecs for each subplot. So after the above loop terminates,secondary_y corresponds only to the value provided forsecondary_y in the spec of the final subplot.

You can see how this causes issues if you set'secondary_y': False for the final subplot only; it breaks shared y-axes for every subplot in the grid.

The fix might be as simple as something like this:

Suggested change

	ifsecondary_y:
	_configure_shared_axes(
	layout,grid_ref,specs,"y",shared_yaxes,row_dir,True
	)
	any_secondary_y=any([spec.get("secondary_y",False)forspec_rowinspecsforspecinspec_row])
	ifany_secondary_y:
	_configure_shared_axes(
	layout,grid_ref,specs,"y",shared_yaxes,row_dir,True
	)