Mesa Interactive

Overview

Mesa Interactive is a specialized Python package designed to provide dynamic visualization and interaction capabilities for Mesa models. It extends the functionalities of the Mesa framework for agent-based modeling.

Quick Installation

To quickly install the package, open your terminal and run:

pip install mesa_interactive

Example: Visualizing a Schelling Segregation Model

This section provides a step-by-step walkthrough to visualize a Schelling Segregation model using Mesa Interactive.

Prerequisites

Ensure that you have mesa-models installed. If not, run the following command:

pip install -U -e git+https://github.com/projectmesa/mesa-examples#egg=mesa-models

Importing Dependencies

Load the essential libraries as follows:

import solara
from mesa_interactive import slide, static
from mesa_interactive.components import create_chart, create_grid, create_markdown
from mesa_interactive.interactive import MesaInteractive
from mesa_models.schelling.model import Schelling

Defining Custom Functions

1. Switch Agent Type: Create a function to toggle an agent's type when clicked on the grid.

def switch_agent_type(model, x, y):
    agent = model.grid.get_cell_list_contents([(x, y)])[0]
    agent.type = 1 - agent.type

Building Components

1. GridView: Construct a grid view, enabling the switch_agent_type function on agent click.

GridView = create_grid("type", on_click=switch_agent_type)

2. Instructions: Add Markdown instructions. These are static and don't rely on model parameters.

Instructions = static(solara.Markdown("Click on an agent to switch its type."))

3. HappyCount: Display the number of satisfied agents via a Markdown component.

HappyCount = create_markdown(
    lambda model: f"**Happy Agents: {model.happy} of {len(model.schedule.agents)}**"
)

4. HappyChart: Implement a time-series chart to track the number of happy agents.

HappyChart = create_chart("happy", "Happy Agents")

Configuring Model Parameters

Define user-adjustable model parameters using sliders:

model_params = {
    "width": 20,
    "height": 20,
    "density": slide(0, 1, 0.1, default=0.65),
    "minority_pc": slide(0, 1, 0.05, default=0.2),
    "homophily": slide(0, 8, 1, default=3),
}

Creating the Interactive Page

1. Initialize the Mesa Interactive interface with the Schelling model, model parameters, and assembled components.

page = MesaInteractive(
    Schelling,
    model_params,
    components=[HappyCount, Instructions, GridView, HappyChart],
    name="Schelling",
    show_dataframe="model",
)

2. To render and display all the components, simply call:

page

Now you have a fully interactive visualization for the Schelling Segregation model!