Update app.py

app.py

@@ -1,11 +1,13 @@
 import streamlit as st
 import matplotlib.pyplot as plt
 import networkx as nx
+import numpy as np
 
 # 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", "Basic: Simple graph Directed"])
+                                  "Basic: Read and write graphs", "Basic: Simple graph", 
+                                  "Basic: Simple graph Directed", "Drawing: Custom Node Position"])
 
 # Function to display properties and graph for Basic: Properties
 def display_graph_properties(G):
@@ -115,6 +117,58 @@ def display_simple_directed_graph(G, pos=None):
     plt.axis("off")
     st.pyplot(plt)
 
+# Function to display Custom Node Position Graphs for Drawing: Custom Node Position
+def display_custom_node_position():
+    st.title("Drawing: Custom Node Position")
+    option = st.radio("Choose a graph type:", ("Default Example", "Create your own"))
+
+    if option == "Default Example":
+        # Default example graph (path graph with custom node position)
+        G = nx.path_graph(20)
+        center_node = 5
+        edge_nodes = set(G) - {center_node}
+        
+        # Ensure the nodes around the circle are evenly distributed
+        pos = nx.circular_layout(G.subgraph(edge_nodes))
+        pos[center_node] = np.array([0, 0])  # Manually specify node position
+        
+        # Draw the graph
+        nx.draw(G, pos, with_labels=True)
+        st.pyplot(plt)
+
+    elif option == "Create your own":
+        # Let the user define a graph with custom 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="0,1\n1,2\n2,3")
+        
+        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))
+
+        # Create the graph and allow user to input custom node positions
+        if st.button("Generate"):
+            G_custom = nx.Graph()
+            G_custom.add_edges_from(edges)
+
+            # Let user define node positions
+            st.write("Enter custom positions for nodes (format: node: x,y). For example, 0: 0,0 or 1: 1,2.")
+            pos_input = st.text_area("Node positions:", value="0: 0,0\n1: 1,1\n2: 2,0")
+            
+            pos = {}
+            if pos_input:
+                pos_list = pos_input.split("\n")
+                for position in pos_list:
+                    node, coordinates = position.split(":")
+                    x, y = map(float, coordinates.split(","))
+                    pos[int(node)] = np.array([x, y])
+
+            # Draw the graph with custom node positions
+            nx.draw(G_custom, pos, with_labels=True)
+            st.pyplot(plt)
+
 # Display Basic: Properties if selected
 if sidebar_option == "Basic: Properties":
     st.title("Basic: Properties")
@@ -247,3 +301,7 @@ elif sidebar_option == "Basic: Simple graph Directed":
             # Set a basic layout (spring layout as default)
             pos = nx.spring_layout(G_custom, seed=42)
             display_simple_directed_graph(G_custom, pos)
+
+# Display Drawing: Custom Node Position if selected
+elif sidebar_option == "Drawing: Custom Node Position":
+    display_custom_node_position()