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",
+                                  "Graph: DAG - Topological Layout"])
 
 # Helper function to draw and display graph
 def draw_graph(G, pos=None, title="Graph Visualization"):
@@ -28,6 +29,82 @@ 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)
 
+def dag_topological_layout():
+    st.title("Graph: DAG - Topological Layout")
+
+    # Sidebar selection for Default Example or Custom Graph
+    graph_mode = st.radio(
+        "Choose a Mode:",
+        ("Default Example", "Create Your Own"),
+        help="Default example shows DAG layout in topological order, or you can create your own DAG."
+    )
+
+    if graph_mode == "Default Example":
+        # Create a Directed Acyclic Graph (DAG)
+        G = nx.DiGraph(
+            [
+                ("f", "a"),
+                ("a", "b"),
+                ("a", "e"),
+                ("b", "c"),
+                ("b", "d"),
+                ("d", "e"),
+                ("f", "c"),
+                ("f", "g"),
+                ("h", "f"),
+            ]
+        )
+
+        # Add layer attribute for multipartite_layout
+        for layer, nodes in enumerate(nx.topological_generations(G)):
+            for node in nodes:
+                G.nodes[node]["layer"] = layer
+
+        # Compute the multipartite_layout using the "layer" node attribute
+        pos = nx.multipartite_layout(G, subset_key="layer")
+
+        # Draw the graph
+        fig, ax = plt.subplots()
+        nx.draw_networkx(G, pos=pos, ax=ax)
+        ax.set_title("DAG layout in topological order")
+        fig.tight_layout()
+        st.pyplot(fig)
+
+    elif graph_mode == "Create Your Own":
+        st.write("### Custom DAG Creation")
+
+        # Inputs for custom DAG creation (nodes and edges)
+        num_nodes = st.slider("Number of Nodes", min_value=2, max_value=10, value=5)
+        edges = []
+
+        for i in range(num_nodes):
+            for j in range(i + 1, num_nodes):
+                if st.checkbox(f"Add edge from {i} to {j}", value=False):
+                    edges.append((i, j))
+
+        # Create the custom DAG
+        G_custom = nx.DiGraph()
+        G_custom.add_edges_from(edges)
+
+        # Add layer attribute for multipartite_layout
+        for layer, nodes in enumerate(nx.topological_generations(G_custom)):
+            for node in nodes:
+                G_custom.nodes[node]["layer"] = layer
+
+        # Compute the multipartite_layout using the "layer" node attribute
+        pos_custom = nx.multipartite_layout(G_custom, subset_key="layer")
+
+        # Draw the custom DAG
+        fig_custom, ax_custom = plt.subplots()
+        nx.draw_networkx(G_custom, pos=pos_custom, ax=ax_custom)
+        ax_custom.set_title("Custom DAG layout in topological order")
+        fig_custom.tight_layout()
+        st.pyplot(fig_custom)
+
+# Display the corresponding page based on sidebar option
+if sidebar_option == "Graph: DAG - Topological Layout":
+    dag_topological_layout()
+
 if sidebar_option == "3D Drawing: Animations of 3D Rotation":
     st.title("3D Drawing: Animations of 3D Rotation")