To resolve the `ModuleNotFoundError` for `matplotlib` in Pyodide, install the package before importing it. Here’s the corrected code:
```python
# Install required packages in Pyodide
import micropip
await micropip.install('numpy')
await micropip.install('matplotlib')
# Original code
import numpy as np
from matplotlib import pyplot as plt
class Node:
def __init__(self, id):
self.id = id
self.state = None
self.instructions = []
def apply_instructions(self):
for instr in self.instructions:
instr.apply()
class Instruction:
def __init__(self, source_node, target_node, effect):
self.source_node = source_node
self.target_node = target_node
self.effect = effect
def apply(self):
self.target_node.state = self.effect(self.source_node.state)
class CausalGraph:
def __init__(self, num_nodes):
self.nodes = [Node(i) for i in range(num_nodes)]
self.edges = []
self.time_steps = 0
def add_edge(self, source_id, target_id, effect):
source_node = self.nodes[source_id]
target_node = self.nodes[target_id]
instruction = Instruction(source_node, target_node, effect)
source_node.instructions.append(instruction)
self.edges.append((source_id, target_id, instruction))
def simulate(self, steps):
for _ in range(steps):
for edge in self.edges:
edge[2].apply()
self.time_steps += 1
def visualize(self):
fig, ax = plt.subplots(figsize=(10, 5))
for edge in self.edges:
ax.plot([edge[0], edge[1]], [self.time_steps, self.time_steps], 'r--')
ax.set_xlim(-1, len(self.nodes))
ax.set_ylim(-1, self.time_steps + 1)
ax.set_xlabel('Nodes')
ax.set_ylabel('Time Steps')
ax.set_title('Causal Graph Simulation')
plt.show()
# Example usage
if __name__ == "__main__":
cg = CausalGraph(5)
cg.add_edge(0, 1, lambda x: x + 1)
cg.add_edge(1, 2, lambda x: x * 2)
cg.add_edge(2, 3, lambda x: x - 1)
cg.add_edge(3, 4, lambda x: x / 2)
cg.nodes[0].state = 10
cg.nodes[1].state = 5
cg.nodes[2].state = 3
cg.nodes[3].state = 7
cg.nodes[4].state = 2
cg.simulate(10)
cg.visualize()
```
# Key Fixes
1. Added `await micropip.install('matplotlib')` to install Matplotlib
2. Ensured dependencies are installed before imports
This will resolve the missing module error and allow the visualization to run.