psychohistory.py

import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import networkx as nx
import numpy as np
import json
import sys
import random

def build_graph_from_json(json_data, G):
    """Builds a graph from JSON data."""
    def add_event(parent_id, event_data, depth):
        """Recursively adds events and subevents to the graph."""
        # Add the current event node
        node_id = len(G.nodes)
        prob = event_data['probability'] / 100.0  # Convert percentage to probability
        pos = (depth, prob, event_data['event_number'])  # Use event_number for z position
        label = event_data['name']  # Use event name as label
        G.add_node(node_id, pos=pos, label=label)
        if parent_id is not None:
            G.add_edge(parent_id, node_id)

        # Add child events
        subevents = event_data.get('subevents', {}).get('event', [])
        if not isinstance(subevents, list):
            subevents = [subevents]  # Ensure subevents is a list

        for subevent in subevents:
            add_event(node_id, subevent, depth + 1)

    # Iterate through all top-level events (this is the corrected part)
    for event_data in json_data.get('events', {}).values():
        add_event(None, event_data, 0)  # Add each event as a root node


def find_paths(G):
    """Finds the paths with the highest and lowest average probability,
       and the longest and shortest durations in graph G."""
    best_path = None
    worst_path = None
    longest_duration_path = None
    shortest_duration_path = None
    best_mean_prob = -1
    worst_mean_prob = float('inf')
    max_duration = -1
    min_duration = float('inf')

    for source in G.nodes:
        for target in G.nodes:
            if source != target:
                all_paths = list(nx.all_simple_paths(G, source=source, target=target))
                for path in all_paths:
                    # Check if all nodes in the path have the 'pos' attribute
                    if not all('pos' in G.nodes[node] for node in path):
                        continue  # Skip paths with nodes missing the 'pos' attribute

                    # Calculate the mean probability of the path
                    probabilities = [G.nodes[node]['pos'][1] for node in path]  # Get node probabilities
                    mean_prob = np.mean(probabilities)

                    # Evaluate path with the highest mean probability
                    if mean_prob > best_mean_prob:
                        best_mean_prob = mean_prob
                        best_path = path

                    # Evaluate path with the lowest mean probability
                    if mean_prob < worst_mean_prob:
                        worst_mean_prob = mean_prob
                        worst_path = path

                    # Calculate path duration
                    x_positions = [G.nodes[node]['pos'][0] for node in path]
                    duration = max(x_positions) - min(x_positions)

                    # Evaluate path with the longest duration
                    if duration > max_duration:
                        max_duration = duration
                        longest_duration_path = path

                    # Evaluate path with the shortest duration
                    if duration < min_duration:
                        min_duration = duration
                        shortest_duration_path = path

    return best_path, best_mean_prob, worst_path, worst_mean_prob, longest_duration_path, shortest_duration_path


def draw_path_3d(G, path, filename='path_plot_3d.png', highlight_color='blue'):
    """Draws only the specific path in 3D using networkx and matplotlib
       and saves the figure to a file."""
    # Create a subgraph containing only the nodes and edges of the path
    H = G.subgraph(path).copy()

    pos = nx.get_node_attributes(G, 'pos')

    # Get data for 3D visualization
    x_vals, y_vals, z_vals = zip(*[pos[node] for node in path])

    fig = plt.figure(figsize=(16, 12))
    ax = fig.add_subplot(111, projection='3d')

    # Assign colors to nodes based on probability
    node_colors = []
    for node in path:
        prob = G.nodes[node]['pos'][1]
        if prob < 0.33:
            node_colors.append('red')
        elif prob < 0.67:
            node_colors.append('blue')
        else:
            node_colors.append('green')

    # Draw nodes
    ax.scatter(x_vals, y_vals, z_vals, c=node_colors, s=700, edgecolors='black', alpha=0.7)

    # Draw edges
    for edge in H.edges():
        x_start, y_start, z_start = pos[edge[0]]
        x_end, y_end, z_end = pos[edge[1]]
        ax.plot([x_start, x_end], [y_start, y_end], [z_start, z_end], color=highlight_color, lw=2)

    # Add labels to nodes
    for node, (x, y, z) in pos.items():
        if node in path:
            ax.text(x, y, z, str(node), fontsize=12, color='black')

    # Set labels and title
    ax.set_xlabel('Time (weeks)')
    ax.set_ylabel('Event Probability')
    ax.set_zlabel('Event Number')
    ax.set_title('3D Event Tree - Path')

    plt.savefig(filename, bbox_inches='tight')  # Save to file with adjusted margins
    plt.close()  # Close the figure to free resources


def draw_global_tree_3d(G, filename='global_tree.png'):
    """Draws the entire graph in 3D using networkx and matplotlib
       and saves the figure to a file."""
    pos = nx.get_node_attributes(G, 'pos')
    labels = nx.get_node_attributes(G, 'label')

    # Check if the graph is empty
    if not pos:
        print("Graph is empty. No nodes to visualize.")
        return

    # Get data for 3D visualization
    x_vals, y_vals, z_vals = zip(*pos.values())

    fig = plt.figure(figsize=(16, 12))
    ax = fig.add_subplot(111, projection='3d')

    # Assign colors to nodes based on probability
    node_colors = []
    for node, (x, prob, z) in pos.items():
        if prob < 0.33:
            node_colors.append('red')
        elif prob < 0.67:
            node_colors.append('blue')
        else:
            node_colors.append('green')

    # Draw nodes
    ax.scatter(x_vals, y_vals, z_vals, c=node_colors, s=700, edgecolors='black', alpha=0.7)

    # Draw edges
    for edge in G.edges():
        x_start, y_start, z_start = pos[edge[0]]
        x_end, y_end, z_end = pos[edge[1]]
        ax.plot([x_start, x_end], [y_start, y_end], [z_start, z_end], color='gray', lw=2)

    # Add labels to nodes
    for node, (x, y, z) in pos.items():
        label = labels.get(node, f"{node}")
        ax.text(x, y, z, label, fontsize=12, color='black')

    # Set labels and title
    ax.set_xlabel('Time')
    ax.set_ylabel('Probability')
    ax.set_zlabel('Event Number')
    ax.set_title('3D Event Tree')

    plt.savefig(filename, bbox_inches='tight')  # Save to file with adjusted margins
    plt.close()  # Close the figure to free resources

def main(json_data):
    G = nx.DiGraph()
    build_graph_from_json(json_data, G)  # Build graph from the provided JSON data

    draw_global_tree_3d(G, filename='global_tree.png')

    best_path, best_mean_prob, worst_path, worst_mean_prob, longest_path, shortest_path = find_paths(G)

    if best_path:
        print(f"\nPath with the highest average probability: {' -> '.join(map(str, best_path))}")
        print(f"Average probability: {best_mean_prob:.2f}")
    if worst_path:
        print(f"\nPath with the lowest average probability: {' -> '.join(map(str, worst_path))}")
        print(f"Average probability: {worst_mean_prob:.2f}")
    if longest_path:
        print(f"\nPath with the longest duration: {' -> '.join(map(str, longest_path))}")
        print(f"Duration: {max(G.nodes[node]['pos'][0] for node in longest_path) - min(G.nodes[node]['pos'][0] for node in longest_path):.2f}")
    if shortest_path:
        print(f"\nPath with the shortest duration: {' -> '.join(map(str, shortest_path))}")
        print(f"Duration: {max(G.nodes[node]['pos'][0] for node in shortest_path) - min(G.nodes[node]['pos'][0] for node in shortest_path):.2f}")

    if best_path:
        draw_path_3d(G, best_path, 'best_path.png', 'blue')
    if worst_path:
        draw_path_3d(G, worst_path, 'worst_path.png', 'red')
    if longest_path:
        draw_path_3d(G, longest_path, 'longest_duration_path.png', 'green')
    if shortest_path:
        draw_path_3d(G, shortest_path, 'shortest_duration_path.png', 'purple')

    return ('global_tree.png','best_path.png','longest_duration_path.png')  # Return the filename of the global tree