Update app.py

app.py

@@ -9,12 +9,15 @@ sidebar_option = st.sidebar.radio("Select an option",
                                   "Basic: Read and write graphs", "Basic: Simple graph", 
                                   "Basic: Simple graph Directed", "Drawing: Custom Node Position"])
 
+# Helper function to draw and display graph
+def draw_graph(G, pos=None, title="Graph Visualization"):
+    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 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))
@@ -22,23 +25,16 @@ def display_graph_properties(G):
         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
-
+        dist[p] = dist.get(p, 0) + 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)}")
@@ -50,13 +46,10 @@ def display_graph_properties(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)
+    draw_graph(G, pos)
 
 # 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)
@@ -74,9 +67,7 @@ def display_read_write_graph(G):
     # 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)
+    draw_graph(H, pos)
 
 # Function to display Simple Graphs for Basic: Simple graph
 def display_simple_graph(G, pos=None):
@@ -131,25 +122,21 @@ def display_custom_node_position():
     pos[center_node] = np.array([0, 0])  # Manually specify node position
     
     # Draw the graph
-    nx.draw(G, pos, with_labels=True)
-    st.pyplot(plt)
+    draw_graph(G, pos)
 
 # 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)
@@ -160,17 +147,14 @@ 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
+        G = nx.grid_2d_graph(5, 5)
         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)
@@ -181,7 +165,6 @@ 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)
@@ -191,32 +174,21 @@ elif sidebar_option == "Basic: Simple graph":
         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)
 
@@ -225,45 +197,31 @@ elif sidebar_option == "Basic: Simple graph Directed":
     st.title("Basic: Simple graph Directed")
     option = st.radio("Choose a graph type:", ("Default Example", "Create your own"))
 
-    # Default example: simple directed graph
     if option == "Default Example":
         G = nx.DiGraph([(0, 3), (1, 3), (2, 4), (3, 5), (3, 6), (4, 6), (5, 6)])
 
-        # Group nodes by column
         left_nodes = [0, 1, 2]
         middle_nodes = [3, 4]
         right_nodes = [5, 6]
 
-        # Set the position according to column (x-coord)
         pos = {n: (0, i) for i, n in enumerate(left_nodes)}
         pos.update({n: (1, i + 0.5) for i, n in enumerate(middle_nodes)})
         pos.update({n: (2, i + 0.5) for i, n in enumerate(right_nodes)})
 
-        # Draw the directed graph
         display_simple_directed_graph(G, pos)
 
-    # Create your own directed 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 directed edges
-        st.write("Enter the directed 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 directed graph
         if st.button("Generate"):
             G_custom = nx.DiGraph()
             G_custom.add_edges_from(edges)
-            
-            # Set a basic layout (spring layout as default)
             pos = nx.spring_layout(G_custom, seed=42)
             display_simple_directed_graph(G_custom, pos)