feat: DH-20808: Add subplot_titles and title parameters to make_subplots #1283

jnumainville · 2026-01-26T22:37:00Z

Added subplot_titles argument to make_subplots that can either pass in a list of new subplot titles or be set to True to maintain existing subplot titles.
Added title argument to make_subplots as well, similar to other charts.

BREAKING CHANGE: Titles passed in from subplots automatically become subplot titles instead of one of them becoming title. Set subplot_titles to False for previous behavior.

…_subplots Co-authored-by: jnumainville <[email protected]>

Co-authored-by: jnumainville <[email protected]>

…ncation logic Co-authored-by: jnumainville <[email protected]>

…title check Co-authored-by: jnumainville <[email protected]>

Co-authored-by: jnumainville <[email protected]>

- Rename use_existing_titles to titles_as_subtitles for clarity - Remove default value annotations from docstrings - Extract title handling logic into get_subplot_titles helper function - Move annotation and title application from unsafe_update_figure to atomic_layer - Add subplot_annotations and overall_title parameters to atomic_layer and layer - Update documentation to use simpler language (left to right, top to bottom instead of row-major) - Update all tests to use titles_as_subtitles - Simplify extract_title_from_figure to always return string Co-authored-by: jnumainville <[email protected]>

- Rename 'overall_title' parameter to 'title' in layer function - Remove unnecessary padding logic from get_subplot_titles (annotations are skipped for missing titles anyway) - Remove erroneous duplicate return statement in atomic_make_subplots Co-authored-by: jnumainville <[email protected]>

jnumainville · 2026-01-27T16:50:19Z

Looks like this needs deephaven/deephaven-core#7596 to pass fully

github-actions · 2026-02-03T20:06:25Z

ui docs preview (Available for 14 days)

github-actions · 2026-02-03T20:21:54Z

ui docs preview (Available for 14 days)

github-actions · 2026-02-03T20:21:59Z

plotly-express docs preview (Available for 14 days)

Copilot

Pull request overview

This pull request adds support for subplot titles and an overall title to the make_subplots function in the Deephaven plotly-express plugin. The implementation allows users to specify individual subplot titles via a list or automatically extract titles from existing figures by setting subplot_titles=True. Additionally, users can now add an overall title to the entire subplot figure.

Changes:

Added subplot_titles and title parameters to make_subplots function
Implemented helper functions for title extraction, annotation creation, and grid position mapping
Updated documentation with examples of the new functionality
Added comprehensive unit tests for the new features
Updated test fixtures for precision handling in datetime comparisons

Reviewed changes

Copilot reviewed 22 out of 28 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py	Core implementation of subplot titles and overall title functionality
plugins/plotly-express/src/deephaven/plot/express/plots/_layer.py	Added support for subplot annotations and title handling in layer function
plugins/plotly-express/test/deephaven/plot/express/plots/test_make_subplots.py	Added comprehensive test coverage for new subplot title features
plugins/plotly-express/docs/sub-plots.md	Updated documentation with examples of subplot titles and overall title usage
plugins/plotly-express/test/deephaven/plot/express/preprocess/*.py	Updated test assertions to use pandas.testing.assert_frame_equal for better precision handling
plugins/plotly-express/test/deephaven/plot/express/plots/test_timeline.py	Updated timeline test to handle datetime precision differences
tests/express.spec.ts	Added integration tests for titles and subplots
tests/app.d/express.py	Added test fixtures using the new functionality
sphinx_ext/sphinx-requirements.txt	Added Sphinx version constraint to prevent incompatibility
plugins/plotly-express/setup.cfg	Bumped deephaven-core dependency to 0.41.1
plugins/plotly-express/docs/snapshots/*.json	Updated documentation snapshots
tests/express.spec.ts-snapshots/*.png	Added visual regression test snapshots

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

plugins/plotly-express/docs/sub-plots.md

github-actions · 2026-02-03T21:57:48Z

plotly-express docs preview (Available for 14 days)

github-actions · 2026-02-03T21:57:51Z

ui docs preview (Available for 14 days)

Copilot

Pull request overview

Copilot reviewed 22 out of 28 changed files in this pull request and generated 2 comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

github-actions · 2026-02-09T17:45:10Z

ui docs preview (Available for 14 days)

github-actions · 2026-02-09T18:32:10Z

plotly-express docs preview (Available for 14 days)

github-actions · 2026-02-09T18:32:15Z

ui docs preview (Available for 14 days)

mattrunyon · 2026-02-09T18:05:14Z

plugins/plotly-express/setup.cfg

 packages=find_namespace:
 install_requires =
-    deephaven-core>=0.37.6
+    deephaven-core>=0.41.1


I don't think this is a version? We have 0.40.x and 41.x

mattrunyon · 2026-02-09T18:25:34Z

plugins/plotly-express/src/deephaven/plot/express/plots/_layer.py

+        title:
+            Title to set for the figure. If False, removes any autogenerated title.
+            If None, leaves the title as is.


How does the autogenerated title apply to subplots? Like what gets generated?

What is the case where you would want to remove auto generated? Could you just set it to empty string instead of False or would that cause some layout issues?

mattrunyon · 2026-02-12T20:47:12Z

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

+      col_starts: List of column start positions
+      col_ends: List of column end positions
+      row_starts: List of row start positions
+      row_ends: List of row end positions


Should add that all of these are in "user's natural index" (top-left is 0)

Does the subplot API take screen coordinates, but plotly uses grid coordinates internally?

mattrunyon · 2026-02-12T20:48:11Z

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

+    rows: int,
+    cols: int,
+) -> list[dict]:
+    """Create annotations for subplot titles


Is this how Plotly does it (as an annotation) or are we doing something different and it must be an annotation?

https://plotly.com/python/subplots/ the "Multiple Subplots with Titles" here.

They also do it with annotations, around here

mattrunyon · 2026-02-12T20:54:01Z

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

+    """Get the list of subplot titles based on parameters
+
+    Args:
+      grid: The grid of figures (already reversed)


I would clarify what reversed is here (bottom-left is 0,0?)

mattrunyon · 2026-02-12T21:06:01Z

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

    col_starts, col_ends = get_domains(column_widths, horizontal_spacing)
-    row_starts, row_ends = get_domains(row_heights, vertical_spacing)
+    # In the case of rows, the last figure is the one at the top, so add an end_margin


Is this always true? Does the order of creating subplots matter?

# This fig.add_trace(row=1, col=1) fig.add_trace(row=2, col=1) # Vs this fig.add_trace(row=2, col=1) fig.add_trace(row=1, col=1)

mattrunyon · 2026-02-12T21:11:16Z

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py

+      subplot_titles:
+        True by default, which automatically extracts and uses titles from the input figures
+        as subplot titles.
+        If False, one of the subplot titles ends up as the chart title.
+        See the title parameter to override this behavior.


Should we prefer an empty list/None instead of boolean + list as the type? Not sure if that would complicate things or if that deviates from plotly

mattrunyon · 2026-02-12T21:19:12Z

plugins/plotly-express/test/deephaven/plot/express/plots/test_make_subplots.py

+    def test_make_subplot_titles_with_grid(self):
+        import src.deephaven.plot.express as dx
+
+        chart1 = dx.scatter(self.source, x="X", y="Y", title="Chart A")
+        chart2 = dx.scatter(self.source, x="X", y="Y", title="Chart B")
+        chart3 = dx.scatter(self.source, x="X", y="Y", title="Chart C")
+        chart4 = dx.scatter(self.source, x="X", y="Y", title="Chart D")
+
+        grid = [[chart1, chart2], [chart3, chart4]]
+        charts = dx.make_subplots(grid=grid).to_dict(self.exporter)


What happens (or should happen) if there is a title on the chart and also subplot_titles passed to make_subplots? Should add a test for that case

mattrunyon · 2026-02-12T21:20:09Z

plugins/plotly-express/test/deephaven/plot/express/preprocess/test_HierarchicalPreprocessor.py

@@ -1,6 +1,7 @@
 import unittest

 from ..BaseTest import BaseTestCase
+import pandas.testing as tm


Just curious why these pandas test changes are in this PR

mattrunyon · 2026-02-12T21:20:57Z

tests/app.d/express.py

+    dx.scatter(express_source, x="Values", y="Values2", title="Subplot 1"),
+    dx.scatter(express_source, x="Values", y="Values2", title="Subplot 2"),
+    cols=2,
+    subplot_titles=True,


Is this explicit true needed? Should we omit it to test default behavior instead?

Copilot AI and others added 12 commits November 7, 2025 20:53

Initial plan

c460b14

Add subplot_titles, use_existing_titles, and title parameters to make…

74d3ae4

…_subplots Co-authored-by: jnumainville <[email protected]>

Apply black formatting to subplots code and tests

8adf354

Co-authored-by: jnumainville <[email protected]>

Apply blacken-docs formatting to sub-plots.md documentation

c339107

Co-authored-by: jnumainville <[email protected]>

Fix row calculation for subplot titles to account for reversed grid

6292cc4

Co-authored-by: jnumainville <[email protected]>

Address code review feedback: improve None handling and add title tru…

287266f

…ncation logic Co-authored-by: jnumainville <[email protected]>

Refactor annotation logic: extract helper function and improve empty …

7a5f519

…title check Co-authored-by: jnumainville <[email protected]>

Simplify title check by removing redundant isinstance

5e6d609

Co-authored-by: jnumainville <[email protected]>

tweaks and testing

a070a6b

Merge remote-tracking branch 'origin/main' into 20808_subplot_titles

a3fb367

jnumainville mentioned this pull request Jan 26, 2026

feat: DH-20808: Add subplot_titles and title parameters to make_subplots #1260

Closed

jnumainville added 2 commits January 29, 2026 11:21

add pytz workaround

5010206

attempt build/test fixes

a361305

snapshots update

70b5bb4

jnumainville requested review from a team, Copilot and mattrunyon and removed request for a team February 3, 2026 20:50

jnumainville marked this pull request as ready for review February 3, 2026 20:50

Copilot started reviewing on behalf of jnumainville February 3, 2026 20:50 View session

github-actions bot requested a review from margaretkennedy February 3, 2026 20:50

Copilot AI reviewed Feb 3, 2026

View reviewed changes

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py Outdated Show resolved Hide resolved

plugins/plotly-express/docs/sub-plots.md Outdated Show resolved Hide resolved

review comments

40d4511

jnumainville requested a review from Copilot February 3, 2026 21:55

Copilot started reviewing on behalf of jnumainville February 3, 2026 21:55 View session

Copilot AI reviewed Feb 3, 2026

View reviewed changes

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py Show resolved Hide resolved

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py Show resolved Hide resolved

jnumainville mentioned this pull request Feb 5, 2026

fix: DH-21383: Convert map center to TypedDict #1285

Open

jnumainville commented Feb 6, 2026

View reviewed changes

plugins/plotly-express/src/deephaven/plot/express/plots/subplots.py Outdated Show resolved Hide resolved

subplot titles default

94c19f2

fix internal logic

790994b

margaretkennedy approved these changes Feb 10, 2026

View reviewed changes

mattrunyon requested changes Feb 12, 2026

View reviewed changes

feat: DH-20808: Add subplot_titles and title parameters to make_subplots #1283

Are you sure you want to change the base?

feat: DH-20808: Add subplot_titles and title parameters to make_subplots #1283

Conversation

jnumainville commented Jan 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

jnumainville commented Jan 27, 2026

Uh oh!

github-actions bot commented Feb 3, 2026

Uh oh!

github-actions bot commented Feb 3, 2026

Uh oh!

github-actions bot commented Feb 3, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

github-actions bot commented Feb 3, 2026

Uh oh!

github-actions bot commented Feb 3, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Uh oh!

github-actions bot commented Feb 9, 2026

Uh oh!

github-actions bot commented Feb 9, 2026

Uh oh!

github-actions bot commented Feb 9, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

jnumainville commented Jan 26, 2026 •

edited

Loading