Mesa 3.0 beta 0

Highlights

We're proud to release the first Mesa 3.0 beta! This pre-release announces that we're ready for Mesa 3.0 to be tested by all our regular users. We try to not making breaking changes anymore, but focus on resolving bugs and imperfections.

In this beta, not so much has changed as in the alphas (we're stabilizing, that's a good sign), but there are still a few notable things:

• Agents now have to be initialized without their unique_id. See #2328 and the Migration guide.
• PropertyLayers can now be visualized! See #2336 for details and some examples, and mesa-examples#214 as a simple example model.
• We reduced the core dependencies of Mesa, so that's a lighter and simpler install. You can now use extras to install the dependencies, for example add [viz] to install all visualisation dependencies: pip install -U --pre mesa[viz]. See #2265 for details.
• The Mesa Overview as fully updated for 3.0. We highly recommend reading though it!
• We made some more progress on the experimental Cell Space, adding movement and integrating the PropertyLayer. Among others, Agents have nu initial movement capabilities for grids. Development continues during the betas and

We plan to release one or two more beta's in the coming weeks, and tag a release candidate and Mesa 3.0 late October. In the v3.0 milestone are the critical items on our todo-list.

You can install this pre-release as usual with:

pip install --upgrade --pre mesa

We're very curious what you think, try it out and ask any questions or share any feedback here!

What's Changed

⚠️ Breaking changes

• update Agent.__init__ to remove deprecation warning by @quaquel in #2328

🎉 New features added

• Visualize PropertyLayers by @EwoutH in #2336

🧪 Experimental features

• Encapsulate cell movement in properties by @quaquel in #2333
• experimental: Integrate PropertyLayers into cell space by @EwoutH in #2319
• Generalize CellAgent by @Corvince in #2292

🛠 Enhancements made

• Reduce core dependencies, split in optional dependencies by @EwoutH in #2265

🐛 Bugs fixed

• viz: stop running and disable buttons when model.running is False by @wang-boyu in #2332

📜 Documentation improvements

• docs: Update overview for Mesa 3.0 by @EwoutH in #2317
• Readthedocs: Add version switch and update URL by @EwoutH in #2324

🔧 Maintenance

• tests: Resolve warnings by removing scheduler and updating arguments by @EwoutH in #2329
• add super call to Model and remove self.schedule by @quaquel in #2334

Other changes

• Deprecate initialize_data_collector by @EwoutH in #2327

Full Changelog: v3.0.0a5...v3.0.0b0