Update src/streamlit_app.py

src/streamlit_app.py

@@ -1,38 +1,8 @@
 import streamlit as st
 import numpy as np
 import matplotlib.pyplot as plt
-import matplotlib
-import os
-import tempfile
 from kinematics_visualizer import Motion1D, Motion2D, KinematicsVisualizer
 
-# Fix matplotlib configuration for HuggingFace Spaces
-try:
-    # Set matplotlib to use a writable temporary directory
-    temp_dir = tempfile.mkdtemp()
-    os.environ['MPLCONFIGDIR'] = temp_dir
-    matplotlib.use('Agg')  # Use non-interactive backend
-except Exception as e:
-    st.warning(f"Matplotlib configuration warning (app will still work): {e}")
-
-def clear_comparison_state():
-    """Clear any lingering comparison state"""
-    try:
-        keys_to_clear = [key for key in st.session_state.keys() if key.startswith('comp_')]
-        for key in keys_to_clear:
-            if key in st.session_state:
-                del st.session_state[key]
-    except Exception:
-        pass  # Silently handle any state clearing issues
-
-def clear_plots():
-    """Safely clear all matplotlib plots"""
-    try:
-        plt.clf()
-        plt.close('all')
-        plt.ioff()  # Turn off interactive mode
-    except Exception:
-        pass
 
 # Configure Streamlit page
 st.set_page_config(
@@ -90,47 +60,21 @@ st.markdown("""
 """, unsafe_allow_html=True)
 
 def main():
-    # Clear plots at the start
-    clear_plots()
-    
     st.markdown('<div class="main-header">🚀 Physics Tutorial: Kinematics</div>', unsafe_allow_html=True)
     
-    # Initialize session state for tutorial selection if not exists
-    if 'tutorial_type' not in st.session_state:
-        st.session_state.tutorial_type = "1D Motion"
-    
     # Sidebar for navigation
     st.sidebar.title("📚 Select Tutorial")
     tutorial_type = st.sidebar.radio(
         "Choose a physics concept:",
-        ["1D Motion", "2D Projectile Motion", "Compare Motions"],
-        index=["1D Motion", "2D Projectile Motion", "Compare Motions"].index(st.session_state.tutorial_type)
+        ["1D Motion", "2D Projectile Motion", "Compare Motions"]
     )
     
-    # Detect tutorial change and clear state
-    if tutorial_type != st.session_state.tutorial_type:
-        st.session_state.tutorial_type = tutorial_type
-        clear_comparison_state()
-        clear_plots()
-        # Force a clean rerun
-        st.rerun()
-    
-    # Clear comparison state when not on comparison tab
-    if tutorial_type != "Compare Motions":
-        clear_comparison_state()
-        clear_plots()
-    
-    # Route to appropriate function
-    try:
-        if tutorial_type == "1D Motion":
-            show_1d_motion()
-        elif tutorial_type == "2D Projectile Motion":
-            show_2d_motion()
-        elif tutorial_type == "Compare Motions":
-            show_motion_comparison()
-    except Exception as e:
-        st.error(f"Error loading tutorial: {str(e)}")
-        st.info("Please refresh the page and try again.")
+    if tutorial_type == "1D Motion":
+        show_1d_motion()
+    elif tutorial_type == "2D Projectile Motion":
+        show_2d_motion()
+    elif tutorial_type == "Compare Motions":
+        show_motion_comparison()
 
 def show_1d_motion():
     st.markdown('<div class="section-header">📏 One-Dimensional Motion</div>', unsafe_allow_html=True)
@@ -530,115 +474,76 @@ def show_motion_comparison():
     
     st.markdown("**Compare up to 3 different projectile motions side by side**")
     
-    # Clear any previous matplotlib figures explicitly
-    clear_plots()
+    # Create placeholders to prevent oscillation
+    plot_placeholder = st.empty()
+    table_placeholder = st.empty()
     
-    # Use session state to prevent oscillation
-    if 'comparison_initialized' not in st.session_state:
-        st.session_state.comparison_initialized = True
-        st.session_state.comp_speed1 = 20.0
-        st.session_state.comp_angle1 = 30.0
-        st.session_state.comp_height1 = 0.0
-        st.session_state.comp_speed2 = 25.0
-        st.session_state.comp_angle2 = 45.0
-        st.session_state.comp_height2 = 0.0
-        st.session_state.comp_speed3 = 30.0
-        st.session_state.comp_angle3 = 60.0
-        st.session_state.comp_height3 = 5.0
+    # Clear any previous matplotlib figures explicitly
+    plt.clf()
+    plt.close('all')
     
     # Create tabs for different trajectories
     tab1, tab2, tab3 = st.tabs(["🚀 Trajectory 1", "🎯 Trajectory 2", "⚽ Trajectory 3"])
     
     trajectories = []
     
-    # Tab 1
+    # Use containers to isolate each tab's content
     with tab1:
         with st.container():
-            st.subheader("Configure Trajectory 1")
             col1, col2 = st.columns(2)
             with col1:
-                speed1 = st.slider("Speed 1 (m/s)", 5.0, 50.0, st.session_state.comp_speed1, key="slider_speed1")
-                angle1 = st.slider("Angle 1 (°)", 0.0, 90.0, st.session_state.comp_angle1, key="slider_angle1")
+                speed1 = st.slider("Speed 1 (m/s)", 5.0, 50.0, 20.0, key="comp_speed1")
+                angle1 = st.slider("Angle 1 (°)", 0.0, 90.0, 30.0, key="comp_angle1")
             with col2:
-                height1 = st.slider("Height 1 (m)", 0.0, 30.0, st.session_state.comp_height1, key="slider_height1")
+                height1 = st.slider("Height 1 (m)", 0.0, 30.0, 0.0, key="comp_height1")
                 
-            # Update session state
-            st.session_state.comp_speed1 = speed1
-            st.session_state.comp_angle1 = angle1
-            st.session_state.comp_height1 = height1
-            
             motion1 = Motion2D(launch_speed=speed1, launch_angle=angle1, launch_height=height1)
             trajectories.append(("Trajectory 1", motion1, 'blue'))
     
-    # Tab 2
     with tab2:
         with st.container():
-            st.subheader("Configure Trajectory 2")
             col1, col2 = st.columns(2)
             with col1:
-                speed2 = st.slider("Speed 2 (m/s)", 5.0, 50.0, st.session_state.comp_speed2, key="slider_speed2")
-                angle2 = st.slider("Angle 2 (°)", 0.0, 90.0, st.session_state.comp_angle2, key="slider_angle2")
+                speed2 = st.slider("Speed 2 (m/s)", 5.0, 50.0, 25.0, key="comp_speed2")
+                angle2 = st.slider("Angle 2 (°)", 0.0, 90.0, 45.0, key="comp_angle2")
             with col2:
-                height2 = st.slider("Height 2 (m)", 0.0, 30.0, st.session_state.comp_height2, key="slider_height2")
+                height2 = st.slider("Height 2 (m)", 0.0, 30.0, 0.0, key="comp_height2")
                 
-            # Update session state
-            st.session_state.comp_speed2 = speed2
-            st.session_state.comp_angle2 = angle2
-            st.session_state.comp_height2 = height2
-            
             motion2 = Motion2D(launch_speed=speed2, launch_angle=angle2, launch_height=height2)
             trajectories.append(("Trajectory 2", motion2, 'red'))
     
-    # Tab 3
     with tab3:
         with st.container():
-            st.subheader("Configure Trajectory 3")
             col1, col2 = st.columns(2)
             with col1:
-                speed3 = st.slider("Speed 3 (m/s)", 5.0, 50.0, st.session_state.comp_speed3, key="slider_speed3")
-                angle3 = st.slider("Angle 3 (°)", 0.0, 90.0, st.session_state.comp_angle3, key="slider_angle3")
+                speed3 = st.slider("Speed 3 (m/s)", 5.0, 50.0, 30.0, key="comp_speed3")
+                angle3 = st.slider("Angle 3 (°)", 0.0, 90.0, 60.0, key="comp_angle3")
             with col2:
-                height3 = st.slider("Height 3 (m)", 0.0, 30.0, st.session_state.comp_height3, key="slider_height3")
+                height3 = st.slider("Height 3 (m)", 0.0, 30.0, 5.0, key="comp_height3")
                 
-            # Update session state
-            st.session_state.comp_speed3 = speed3
-            st.session_state.comp_angle3 = angle3
-            st.session_state.comp_height3 = height3
-            
             motion3 = Motion2D(launch_speed=speed3, launch_angle=angle3, launch_height=height3)
             trajectories.append(("Trajectory 3", motion3, 'green'))
     
-    # Create comparison plot in a separate container
-    st.markdown("---")
-    st.markdown("### 📈 Trajectory Comparison Plot")
-    
-    plot_container = st.container()
-    with plot_container:
+    # Update plot using placeholder (prevents oscillation)
+    with plot_placeholder.container():
         try:
-            # Create figure with explicit cleanup
+            plt.close('all')
             fig, ax = plt.subplots(figsize=(12, 8))
             
             max_range = 0
-            valid_trajectories = 0
-            
             for name, motion, color in trajectories:
                 try:
                     data = motion.trajectory_data(motion.calculate_flight_time())
                     if len(data['x']) > 0:
                         ax.plot(data['x'], data['y'], linewidth=3, label=name, color=color)
-                        
-                        # Mark launch and landing points
                         ax.plot(motion.launch_x, motion.launch_height, 'o', markersize=8, color=color, alpha=0.7)
-                        if len(data['x']) > 0:
-                            ax.plot(data['x'][-1], data['y'][-1], 's', markersize=8, color=color, alpha=0.7)
-                            max_range = max(max_range, data['x'][-1] if data['x'][-1] > 0 else 0)
-                        valid_trajectories += 1
+                        ax.plot(data['x'][-1], data['y'][-1], 's', markersize=8, color=color, alpha=0.7)
+                        max_range = max(max_range, data['x'][-1] if data['x'][-1] > 0 else 0)
                 except Exception as e:
-                    st.warning(f"Could not plot {name}: {str(e)}")
+                    st.error(f"Error plotting {name}: {str(e)}")
                     continue
             
-            # Only proceed if we have valid data
-            if valid_trajectories > 0 and max_range > 0:
+            if max_range > 0:
                 ax.set_xlabel('Horizontal Position (m)', fontsize=12)
                 ax.set_ylabel('Vertical Position (m)', fontsize=12)
                 ax.set_title('Trajectory Comparison', fontsize=16, fontweight='bold')
@@ -647,7 +552,6 @@ def show_motion_comparison():
                 ax.set_ylim(bottom=0)
                 ax.set_xlim(0, max_range * 1.1)
                 
-                # Display plot with explicit cleanup
                 st.pyplot(fig, clear_figure=True)
             else:
                 st.warning("No valid trajectory data to display")
@@ -655,19 +559,12 @@ def show_motion_comparison():
         except Exception as e:
             st.error(f"Error creating comparison plot: {str(e)}")
         finally:
-            # Always clean up
-            try:
-                plt.close(fig)
-                plt.close('all')
-            except:
-                pass
-    
-    # Comparison table
-    st.markdown("---")
-    st.markdown("### 📋 Trajectory Comparison Table")
+            plt.close('all')
     
-    table_container = st.container()
-    with table_container:
+    # Update table using placeholder (prevents oscillation)
+    with table_placeholder.container():
+        st.markdown("### 📋 Trajectory Comparison Table")
+        
         try:
             comparison_data = []
             for name, motion, _ in trajectories:
@@ -683,7 +580,6 @@ def show_motion_comparison():
                         "Max Height (m)": f"{info['max_height']:.1f}"
                     })
                 except Exception as e:
-                    st.warning(f"Could not get data for {name}: {str(e)}")
                     continue
             
             if comparison_data: