Update app.py

app.py

@@ -319,6 +319,39 @@ def analyze_subregion(state, header, region_start, region_end):
 # 9. COMPARISON ANALYSIS FUNCTIONS
 ###############################################################################
 
+def compute_shap_difference(shap1_norm, shap2_norm):
+    """Compute the SHAP difference between normalized sequences"""
+    return shap2_norm - shap1_norm
+
+def plot_comparative_heatmap(shap_diff, title="SHAP Difference Heatmap"):
+    """
+    Plot heatmap using relative positions (0-100%)
+    """
+    heatmap_data = shap_diff.reshape(1, -1)
+    extent = max(abs(np.min(shap_diff)), abs(np.max(shap_diff)))
+    
+    fig, ax = plt.subplots(figsize=(12, 1.8))
+    cmap = get_zero_centered_cmap()
+    cax = ax.imshow(heatmap_data, aspect='auto', cmap=cmap, vmin=-extent, vmax=extent)
+    
+    # Create percentage-based x-axis ticks
+    num_ticks = 5
+    tick_positions = np.linspace(0, shap_diff.shape[0]-1, num_ticks)
+    tick_labels = [f"{int(x*100)}%" for x in np.linspace(0, 1, num_ticks)]
+    ax.set_xticks(tick_positions)
+    ax.set_xticklabels(tick_labels)
+    
+    cbar = plt.colorbar(cax, orientation='horizontal', pad=0.25, aspect=40, shrink=0.8)
+    cbar.ax.tick_params(labelsize=8)
+    cbar.set_label('SHAP Difference (Seq2 - Seq1)', fontsize=9, labelpad=5)
+    
+    ax.set_yticks([])
+    ax.set_xlabel('Relative Position in Sequence', fontsize=10)
+    ax.set_title(title, pad=10)
+    plt.subplots_adjust(bottom=0.25, left=0.05, right=0.95)
+    
+    return fig
+    
 def calculate_adaptive_parameters(len1, len2):
     """
     Calculate adaptive parameters based on sequence lengths and their difference.