Add render interval slider to control visualization update frequency

[HMNS19]

Summary

This PR adds a render interval slider to the SolaraViz visualization system, allowing users to control how frequently plots and visualizations are updated during model simulation. This feature significantly improves performance when working with complex visualizations or multiple plots.

Motive

When running models with multiple or complex visualizations, plotting components (especially Matplotlib) can become a performance bottleneck. This enhancement allows users to reduce visualization update frequency while maintaining full simulation speed, addressing the performance issues raised in #2579.

Implementation

• Added a render_interval parameter to SolaraViz that defaults to 1
• Implemented a slider control (1-100, step size 2) to adjust the render interval
• Modified the do_step() function in both ModelController and SimulatorController to:
  • Run multiple simulation steps based on the render interval
  • Only update visualizations after completing all steps in the interval
• Added proper documentation and type hints for the new parameter

Usage Examples

The render interval slider appears automatically in the visualization interface.

• Before
  
• After
  

Additional Notes

• The render interval is separate from the play interval - it controls visualization updates while the play interval controls simulation speed
• The implementation maintains backward compatibility and doesn't affect model execution logic

[github-actions]

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
BoltzmannWealth	small	🔵 +0.6% [-0.1%, +1.4%]	🔵 -0.0% [-0.1%, +0.1%]
BoltzmannWealth	large	🔵 -0.5% [-0.9%, -0.1%]	🔵 +0.5% [-0.1%, +1.1%]
Schelling	small	🔵 +1.3% [+1.0%, +1.7%]	🔵 +0.1% [-0.1%, +0.2%]
Schelling	large	🔵 +0.6% [+0.3%, +1.0%]	🔵 -1.1% [-1.9%, -0.4%]
WolfSheep	small	🔵 -0.3% [-0.8%, +0.3%]	🔵 +1.5% [-3.3%, +5.8%]
WolfSheep	large	🔵 -0.6% [-1.4%, -0.0%]	🔵 +0.3% [-1.1%, +1.6%]
BoidFlockers	small	🔵 -1.5% [-2.1%, -1.0%]	🔵 +0.4% [-0.3%, +1.2%]
BoidFlockers	large	🔵 -1.2% [-1.9%, -0.6%]	🔵 -0.8% [-1.2%, -0.4%]

[EwoutH]

@HMNS19 thanks for the PR! Is it already ready for a first round of review?

[HMNS19]

@EwoutH The work is almost ready for the first round of review. For the most part, the execution speed has improved, but it’s not as fast as expected for a few models. I’m currently working on optimizing those. I should have it ready in a day or two. Let me know if you'd like me to proceed with the review or wait until it's fully optimized.

[EwoutH]

Thanks for working on it and providing an update. One thing I notice is that you change every example model. Ideally, I would like a generalized solution, directly in SolaraViz.

Like in this PR:

• Add Interactive Play Interval Control to Mesa Visualization #2540

CC @Corvince @AdamZh0u

[HMNS19]

Understood, will work on it. Thank you for the feedback and the reference!

[github-actions]

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
BoltzmannWealth	small	🔵 -4.0% [-6.1%, -1.7%]	🔵 +0.8% [+0.7%, +0.9%]
BoltzmannWealth	large	🔵 -1.0% [-1.3%, -0.6%]	🔵 +0.4% [-0.9%, +1.5%]
Schelling	small	🔵 -0.8% [-1.2%, -0.5%]	🔵 +0.0% [-0.1%, +0.1%]
Schelling	large	🔵 -0.9% [-1.2%, -0.6%]	🔵 +1.7% [+1.2%, +2.1%]
WolfSheep	small	🔵 -0.6% [-1.0%, -0.1%]	🟢 -15.0% [-19.7%, -10.2%]
WolfSheep	large	🔵 -1.1% [-1.6%, -0.6%]	🔵 +0.5% [-0.3%, +1.5%]
BoidFlockers	small	🔵 +2.3% [+1.6%, +3.0%]	🔵 +2.4% [+1.5%, +3.3%]
BoidFlockers	large	🔵 +2.3% [+1.6%, +3.0%]	🔵 +3.5% [+2.9%, +4.0%]

[EwoutH]

Thanks, code looks good, have you tested it?

I will review later today.

[HMNS19]

Yes, I have tested the example models, and they are working as expected. Most of them respond with very minimal latency after clicking the step button. However, the Epstein model takes around 2 seconds of latency when the step interval is set to a high value like 100. I suspect this might be due to factors unrelated to the slider feature.

[EwoutH]

This works perfect, and is really useful! Glad to see it could be done the same way as in #2540.

I do find the naming currently not the most intuitive, both of play_interval and step_interval. Maybe we can think of some better names, any suggestions?

[EwoutH]

Maybe render_interval?

[HMNS19]

Sure, renaming step_interval to render_interval makes much more sense. However, I’m wondering what we should do about the step button in that case. Since ideally clicking on step should increment step by 1, but it currently depends on the value of the step_interval slider. Should we modify its name to match render_interval so the users don't get confused about why the step button's value also changes.
And if we keep the step button to increment the step by 1 regardless of the slider value, it could cause a mismatch between the current step and the current plot, as the value of the slider would differ.

Would you like me to proceed with any changes based on this?

[EwoutH]

That's a very good catch. For now, I'm okay with leaving it as is, to not make this PR too big. But maybe document this well in the docstring / comments.

CC @quaquel @Corvince.

[EwoutH]

I would like to call it render_interval by the way.

[HMNS19]

I've made the necessary changes and renamed it to render_interval as you suggested. Let me know if any other changes are needed!

[EwoutH]

@HMNS19 Looks good! I cleaned up the PR a little bit (you changed some unrelated files) and updated the PR title and description.

Finally, could you a screenshot of how the slider now looks to the PR description?