Update app.py

app.py

@@ -20,7 +20,8 @@ sidebar_option = st.sidebar.radio("Select an option",
                                   "Drawing: Multipartite Layout", "Drawing: Node Colormap",
                                   "Drawing: Rainbow Coloring", "Drawing: Random Geometric Graph","Drawing: Self-loops",
                                   "Drawing: Simple Path", "Drawing: Spectral Embedding", "Drawing: Traveling Salesman Problem",
-                                  "Drawing: Weighted Graph", "3D Drawing: Animations of 3D Rotation", "3D Drawing: Basic Matplotlib"])
+                                  "Drawing: Weighted Graph", "3D Drawing: Animations of 3D Rotation", "3D Drawing: Basic Matplotlib",
+                                  "Graphviz Layout: Lanl Routes"])
 
 # Helper function to draw and display graph
 def draw_graph(G, pos=None, title="Graph Visualization"):
@@ -28,6 +29,91 @@ def draw_graph(G, pos=None, title="Graph Visualization"):
     nx.draw(G, pos=pos, with_labels=True, node_color='lightblue', node_size=500, font_size=10, font_weight='bold')
     st.pyplot(plt)
 
+# Default example: Lanl Routes graph
+def lanl_graph():
+    """Return the LANL internet view graph from lanl.edges"""
+    try:
+        fh = open("lanl_routes.edgelist")
+    except OSError:
+        print("lanl.edges not found")
+        raise
+
+    G = nx.Graph()
+
+    time = {}
+    time[0] = 0  # assign 0 to center node
+    for line in fh.readlines():
+        (head, tail, rtt) = line.split()
+        G.add_edge(int(head), int(tail))
+        time[int(head)] = float(rtt)
+
+    # get largest component and assign ping times to G0time dictionary
+    Gcc = sorted(nx.connected_components(G), key=len, reverse=True)[0]
+    G0 = G.subgraph(Gcc)
+    G0.rtt = {}
+    for n in G0:
+        G0.rtt[n] = time[n]
+
+    return G0
+
+
+# Streamlit Layout for Graphviz Layout: Lanl Routes
+def graphviz_layout_lanl_routes():
+    st.title("Graphviz Layout: Lanl Routes")
+
+    # Sidebar selection for Default Example or Custom Graph
+    graph_mode = st.radio(
+        "Choose a Mode:",
+        ("Default Example", "Create Your Own"),
+        help="Default example shows LANL routes, or you can create your own custom graph."
+    )
+
+    if graph_mode == "Default Example":
+        # Load LANL graph and visualize
+        G = lanl_graph()
+
+        st.write("Graph Summary:")
+        st.write(G)
+        st.write(f"{nx.number_connected_components(G)} connected components")
+
+        # Create and display the graph
+        plt.figure(figsize=(8, 8))
+        # Use graphviz to find radial layout
+        pos = nx.nx_agraph.graphviz_layout(G, prog="twopi", root=0)
+
+        # Draw nodes, coloring by rtt ping time
+        options = {"with_labels": False, "alpha": 0.5, "node_size": 15}
+        nx.draw(G, pos, node_color=[G.rtt[v] for v in G], **options)
+
+        # Adjust the plot limits
+        xmax = 1.02 * max(xx for xx, yy in pos.values())
+        ymax = 1.02 * max(yy for xx, yy in pos.values())
+        plt.xlim(0, xmax)
+        plt.ylim(0, ymax)
+        st.pyplot(plt)
+
+    elif graph_mode == "Create Your Own":
+        st.write("### Custom Graph Creation")
+
+        # Input form for creating custom graph
+        num_nodes = st.slider("Number of Nodes", min_value=2, max_value=50, value=10)
+        num_edges = st.slider("Number of Edges", min_value=1, max_value=num_nodes*(num_nodes-1)//2, value=10)
+
+        # Generate custom graph
+        G_custom = nx.gnm_random_graph(num_nodes, num_edges)
+
+        st.write("Generated Custom Graph:")
+        st.write(G_custom)
+
+        # Use graphviz layout
+        pos = nx.nx_agraph.graphviz_layout(G_custom, prog="twopi")
+        nx.draw(G_custom, pos, with_labels=True, node_size=500, node_color="lightblue", font_size=10)
+        st.pyplot(plt)
+
+# Display the corresponding page based on sidebar option
+if sidebar_option == "Graphviz Layout: Lanl Routes":
+    graphviz_layout_lanl_routes()
+
 if sidebar_option == "3D Drawing: Animations of 3D Rotation":
     st.title("3D Drawing: Animations of 3D Rotation")