Update app.py

app.py

@@ -2,9 +2,10 @@ import streamlit as st
 import matplotlib.pyplot as plt
 import networkx as nx
 
-# Add a sidebar with options
+# Sidebar for selecting an option
 sidebar_option = st.sidebar.radio("Select an option", 
-                                 ["Select an option", "Basic: Properties", "Basic: Read and write graphs"])
+                                 ["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):
@@ -75,6 +76,26 @@ def display_read_write_graph(G):
     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")
@@ -116,3 +137,47 @@ elif sidebar_option == "Basic: Read and write graphs":
             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)