import streamlit as st import matplotlib.pyplot as plt import networkx as nx # Sidebar for selecting an option sidebar_option = st.sidebar.radio("Select an option", ["Select an option", "Basic: Properties", "Basic: Read and write graphs", "Basic: Simple graph"]) # Function to display properties and graph for Basic: Properties def display_graph_properties(G): # Initialize a list for path lengths pathlengths = [] # Display the source-target shortest path lengths st.write("### Source vertex {target:length, }") for v in G.nodes(): spl = dict(nx.single_source_shortest_path_length(G, v)) st.write(f"Vertex {v}: {spl}") for p in spl: pathlengths.append(spl[p]) # Calculate and display the average shortest path length avg_path_length = sum(pathlengths) / len(pathlengths) st.write(f"### Average shortest path length: {avg_path_length}") # Calculate and display the distribution of path lengths dist = {} for p in pathlengths: if p in dist: dist[p] += 1 else: dist[p] = 1 st.write("### Length #paths") for d in sorted(dist.keys()): st.write(f"Length {d}: {dist[d]} paths") # Display the graph metrics with a "Properties" heading st.write("### Properties") st.write(f"Radius: {nx.radius(G)}") st.write(f"Diameter: {nx.diameter(G)}") st.write(f"Eccentricity: {nx.eccentricity(G)}") st.write(f"Center: {nx.center(G)}") st.write(f"Periphery: {nx.periphery(G)}") st.write(f"Density: {nx.density(G)}") # Visualize the graph st.write("### Graph Visualization") pos = nx.spring_layout(G, seed=3068) # Seed layout for reproducibility plt.figure(figsize=(8, 6)) nx.draw(G, pos=pos, with_labels=True, node_color='lightblue', node_size=500, font_size=10, font_weight='bold') st.pyplot(plt) # Function to display graph for Basic: Read and write graphs def display_read_write_graph(G): # Print the adjacency list of the graph st.write("### Adjacency List:") for line in nx.generate_adjlist(G): st.write(line) # Write the graph's edge list to a file st.write("### Writing Edge List to 'grid.edgelist' file:") nx.write_edgelist(G, path="grid.edgelist", delimiter=":") st.write("Edge list written to 'grid.edgelist'") # Read the graph from the edge list st.write("### Reading Edge List from 'grid.edgelist' file:") H = nx.read_edgelist(path="grid.edgelist", delimiter=":") st.write("Edge list read into graph H") # Visualize the graph st.write("### Graph Visualization:") pos = nx.spring_layout(H, seed=200) # Seed for reproducibility plt.figure(figsize=(8, 6)) nx.draw(H, pos, with_labels=True, node_color='lightblue', node_size=500, font_size=10, font_weight='bold') st.pyplot(plt) # Function to display Simple Graphs for Basic: Simple graph def display_simple_graph(G, pos=None): options = { "font_size": 36, "node_size": 3000, "node_color": "white", "edgecolors": "black", "linewidths": 5, "width": 5, } # Draw the network nx.draw_networkx(G, pos, **options) # Set margins for the axes so that nodes aren't clipped ax = plt.gca() ax.margins(0.20) plt.axis("off") st.pyplot(plt) # Display Basic: Properties if selected if sidebar_option == "Basic: Properties": st.title("Basic: Properties") option = st.radio("Choose a graph type:", ("Default Example", "Create your own")) # Default example: 5x5 grid graph if option == "Default Example": G = nx.lollipop_graph(4, 6) display_graph_properties(G) # Create your own graph elif option == "Create your own": num_nodes = st.number_input("Number of nodes:", min_value=2, max_value=50, value=5) num_edges = st.number_input("Number of edges per group (for lollipop graph):", min_value=1, max_value=10, value=3) # Button to generate the graph if st.button("Generate"): if num_nodes >= 2 and num_edges >= 1: G_custom = nx.lollipop_graph(num_nodes, num_edges) display_graph_properties(G_custom) # Display Basic: Read and write graphs if selected elif sidebar_option == "Basic: Read and write graphs": st.title("Basic: Read and write graphs") option = st.radio("Choose a graph type:", ("Default Example", "Create your own")) # Default example: 5x5 grid graph if option == "Default Example": G = nx.grid_2d_graph(5, 5) # 5x5 grid display_read_write_graph(G) # Create your own graph elif option == "Create your own": rows = st.number_input("Number of rows:", min_value=2, max_value=20, value=5) cols = st.number_input("Number of columns:", min_value=2, max_value=20, value=5) # Button to generate the graph if st.button("Generate"): if rows >= 2 and cols >= 2: G_custom = nx.grid_2d_graph(rows, cols) display_read_write_graph(G_custom) # Display Basic: Simple Graph if selected elif sidebar_option == "Basic: Simple graph": st.title("Basic: Simple graph") option = st.radio("Choose a graph type:", ("Default Example", "Create your own")) # Default example: simple undirected graph if option == "Default Example": G = nx.Graph() G.add_edge(1, 2) G.add_edge(1, 3) G.add_edge(1, 5) G.add_edge(2, 3) G.add_edge(3, 4) G.add_edge(4, 5) # explicitly set positions for visualization pos = {1: (0, 0), 2: (-1, 0.3), 3: (2, 0.17), 4: (4, 0.255), 5: (5, 0.03)} display_simple_graph(G, pos) # Create your own graph elif option == "Create your own": num_nodes = st.number_input("Number of nodes:", min_value=2, max_value=20, value=5) edges = [] # Let the user define edges st.write("Enter the edges (as pairs of nodes) separated by commas. For example, 1,2 or 3,4.") edge_input = st.text_area("Edges:", value="1,2\n1,3\n2,3") # Parse the edges if edge_input: edge_list = edge_input.split("\n") for edge in edge_list: u, v = map(int, edge.split(",")) edges.append((u, v)) # Button to generate the graph if st.button("Generate"): G_custom = nx.Graph() G_custom.add_edges_from(edges) # Set a basic layout (spring layout as default) pos = nx.spring_layout(G_custom, seed=42) display_simple_graph(G_custom, pos)