Update app.py

app.py

@@ -207,9 +207,6 @@ def plot_linear_heatmap(shap_means, title="Per-base SHAP Heatmap", start=None, e
     - Negative = blue
     - 0 = white
     - Positive = red
-    We'll force the range to be symmetrical around 0 by using:
-      vmin=-extent, vmax=+extent
-    so 0 is in the middle.
     """
     if start is not None and end is not None:
         local_shap = shap_means[start:end]
@@ -217,11 +214,10 @@ def plot_linear_heatmap(shap_means, title="Per-base SHAP Heatmap", start=None, e
     else:
         local_shap = shap_means
         subtitle = ""
-    
+        
     if len(local_shap) == 0:
-        # Edge case: no data to plot
         local_shap = np.array([0.0])
-    
+        
     # Build 2D array for imshow
     heatmap_data = local_shap.reshape(1, -1)
     
@@ -233,25 +229,46 @@ def plot_linear_heatmap(shap_means, title="Per-base SHAP Heatmap", start=None, e
     # Create custom colormap
     custom_cmap = get_zero_centered_cmap()
     
-    fig, ax = plt.subplots(figsize=(12, 2))
+    # Create figure with adjusted height ratio
+    fig, ax = plt.subplots(figsize=(12, 1.8))  # Reduced height
+    
+    # Plot heatmap
     cax = ax.imshow(
-        heatmap_data, 
-        aspect='auto', 
+        heatmap_data,
+        aspect='auto',
         cmap=custom_cmap,
         vmin=-extent,
         vmax=+extent
     )
     
-    # Place colorbar below with plenty of margin
-    cbar = plt.colorbar(cax, orientation='horizontal', pad=0.35)
-    cbar.set_label('SHAP Contribution (negative=blue, zero=white, positive=red)')
-
+    # Configure colorbar with more subtle positioning
+    cbar = plt.colorbar(
+        cax,
+        orientation='horizontal',
+        pad=0.25,  # Reduced padding
+        aspect=40,  # Make colorbar thinner
+        shrink=0.8  # Make colorbar shorter than plot width
+    )
+    
+    # Style the colorbar
+    cbar.ax.tick_params(labelsize=8)  # Smaller tick labels
+    cbar.set_label(
+        'SHAP Contribution',
+        fontsize=9,
+        labelpad=5
+    )
+    
+    # Configure main plot
     ax.set_yticks([])
-    ax.set_xlabel('Position in Sequence')
-    ax.set_title(f"{title}{subtitle}")
+    ax.set_xlabel('Position in Sequence', fontsize=10)
+    ax.set_title(f"{title}{subtitle}", pad=10)
     
-    # Extra bottom margin so colorbar won't overlap x-axis labels
-    plt.subplots_adjust(bottom=0.4)
+    # Fine-tune layout
+    plt.subplots_adjust(
+        bottom=0.25,  # Reduced bottom margin
+        left=0.05,    # Tighter left margin
+        right=0.95    # Tighter right margin
+    )
     
     return fig