GoL_fast: Add metrics, datacollector and measure viz

- Add two metrics to the model
- Collect those with the datacollector
- Plot them as measures in SolaraViz

Author: EwoutH

examples/conways_game_of_life_fast/app.py

@@ -23,6 +23,7 @@
 page = SolaraViz(
     GameOfLifeModel,
     model_params,
+    measures=["Cells alive", "Fraction alive"],
     space_drawer=None,
     name="Game of Life Model",
 )

examples/conways_game_of_life_fast/model.py

@@ -1,8 +1,9 @@
 import numpy as np
-from mesa import Model
+from mesa import DataCollector, Model
 from mesa.space import PropertyLayer
 from scipy.signal import convolve2d
 
+
 # fmt: off
 class GameOfLifeModel(Model):
     def __init__(self, width=10, height=10, alive_fraction=0.2):
@@ -12,6 +13,16 @@ def __init__(self, width=10, height=10, alive_fraction=0.2):
         # Randomly set cells to alive
         self.cell_layer.data = np.random.choice([True, False], size=(width, height), p=[alive_fraction, 1 - alive_fraction])
 
+        # Metrics and datacollector
+        self.cells = width * height
+        self.alive_count = 0
+        self.alive_fraction = 0
+        self.datacollector = DataCollector(
+            model_reporters={"Cells alive": "alive_count",
+                             "Fraction alive": "alive_fraction"}
+        )
+        self.datacollector.collect(self)
+
     def step(self):
         self._advance_time()
         # Define a kernel for counting neighbors. The kernel has 1s around the center cell (which is 0).
@@ -34,3 +45,8 @@ def step(self):
             # Rule for live cells
             np.logical_and(~self.cell_layer.data, neighbor_count == 3)  # Rule for dead cells
         )
+
+        # Metrics
+        self.alive_count = np.sum(self.cell_layer.data)
+        self.alive_fraction = self.alive_count / self.cells
+        self.datacollector.collect(self)