Normalize flow centers to unit direction vectors

app.py

@@ -93,12 +93,19 @@ def process_json(json_file, background=None):
     if labels is None:
         return None, {"error":"Insufficient data for clustering."}
 
+    # --- Normalize flow centers to unit direction vectors ---
+    centers = np.array(centers)
+    norms = np.linalg.norm(centers, axis=1, keepdims=True) + 1e-6
+    centers = centers / norms
+    
     img_path = draw_flow_overlay(vectors, labels, centers, background)
+    
     stats = {
         "num_vectors": int(len(vectors)),
         "dominant_flows": int(len(centers)),
         "flow_centers": centers.tolist()
     }
+
     return img_path, stats