frontend: python frontend for Mesa-Geo

[wang-boyu]

What's the problem this feature will solve?

Mesa v2.1 has introduced a mesa.experimental namespace that contains JupyterViz for model visualization in Jupyter notebooks (see projectmesa/mesa#1698 and projectmesa/mesa#1726).

It would be great to similarly have a corresponding set of widgets to visualize GeoSpaces in Jupyter notebooks and web apps too.

Describe the solution you'd like

Either extend the JupyterViz class or have a new class for Mesa-Geo. Currently Mesa uses the Solara framework to create UI components.

Additional context

• Pure Python Frontend for Mesa mesa#1622
• Visualization Tutorial in Mesa
• Map visualization using ipyleaflet in Solara
• ipyleaflet advanced
• pydeck

[wang-boyu]

Hi @Corvince, will you be interested in taking a look at this? @tpike3 and I are probably going to talk about Mesa & Mesa-Geo in an upcoming conference in early Nov. We're thinking to create a tutorial using one of our example models.

Sorry about this short notice. But having a Solora frontend for Mesa-Geo would be super useful : )

[Corvince]

Sorry, I thought I had already answered here. Yes, I would be interested to implement a solara-based frontend. In fact I am working in this right now

[wang-boyu]

Great! Looking forward to your implementation. This will be very helpful.

[Corvince]

An update on things I tried so far:

I wanted to leverage Ipyleaflet to have a leaflet map that is similar to what is included currently with the old frontend. After some troubles converting the agents to a compatible GeoJSON format (solara had some issues), I realized this is not needed and we can just pass in a GeoDataFrame.

We can get that easily with

gdf = model.space.get_agents_as_GeoDataFrame().to_crs("epsg:4326")

With this we can create a ipyleaflet map with something like this

import ipyleaflet

center_default = (53.2305799, 6.5323552)
zoom_default = 5

ipyleaflet.Map(
    center=center_default,
    zoom=zoom_default,
    layers=[
        ipyleaflet.TileLayer(),
        ipyleaflet.GeoData(
            geo_dataframe=gdf,
            style={
                "color": "blue",
                "fillColor": "#3366cc",
                "opacity": 0.05,
                "weight": 1.9,
                "dashArray": "2",
                "fillOpacity": 0.6,
            },
        ),
    ],
)

The problematic thing is coloring the agents based on some property. In leaflet we could define the color in terms of its feature with a function that maps a feature to a color. But this doesn't seem to be possible with IPyleaflet. We could probably create different layers for each color, but I haven't tried.

The other possibility would be to leverage Altair. Here we can define the colors decleratively like so:

import altair as alt

alt.Chart(data=gdf).mark_geoshape().encode(color="atype:O")

However, including a basemap is not super well supported, but might be possible, see vega/vega-lite#5758

And the output needs some finetuning.

But I won't be able to investigate this further until beginning of November. So whats the current timeline for the tutorial @wang-boyu ?

[wang-boyu]

I'm so glad that you're looking into this! Thank you! Was worried about it in the past few days.

There is a dev meeting tomorrow and I'll discuss with @tpike3 about the tutorial. After that I'll post an update here.

[tpike3]

The tutorial is at the beginning of November (Nov2nd or 3rd) @Corvince would you have a branch you can push so I can just build off what you have already done?

[Corvince]

Unfortunately not, but it boils down to the code snippets I posted. I can try to assist if you have questions, but I don't have access to my laptop until Nov.

But both approaches should be possible to wrap in a function like the current grid or space views that accept model and agent_portrayal as their arguments. From there you can generate the geodataframe and return either the solara leaflet or Altair figure

[wang-boyu]

Since we're not really ready for the tutorial, we're going to skip the CSSSA session this year (@tpike3 will still be there to give a Mesa tutorial and may possibly mention Mesa-Geo briefly, but not a full tutorial for Mesa-Geo).

The next window is the online tutorial series from CSSSA (link to the Mesa online tutorial by @tpike3: youtu.be/8P5P7NpCx5o) which is currently scheduled at Feb 2024 for Mesa-Geo. Would be great if we can have the feature and the tutorial ready by then : )

[Corvince]

That sounds doable!