diff --git a/src/napatrackmater/Trackvector.py b/src/napatrackmater/Trackvector.py
index df7b4df7..e745cb20 100644
--- a/src/napatrackmater/Trackvector.py
+++ b/src/napatrackmater/Trackvector.py
@@ -2137,19 +2137,21 @@ def convert_tracks_to_simple_arrays(
     
 
 def compute_raw_matrix(track_arrays, t_delta):
-    
     track_duration = track_arrays.shape[0]
     t_delta = int(t_delta)
-    if track_duration  < t_delta:
-        #zero pad
-        pad_rows = t_delta - track_duration
-        
-        # Pad with the last row and then zeros
+    
+    if track_duration < t_delta:
+        repetitions = t_delta - track_duration
         last_row = track_arrays[-1, :]
-        zero_pad = np.zeros((pad_rows, track_arrays.shape[1]))
-        track_arrays = np.vstack((track_arrays, np.tile(last_row, (pad_rows, 1)), zero_pad))
+        repeated_rows = np.tile(last_row, (repetitions, 1))
+        result_matrix = np.vstack([track_arrays, repeated_rows])
+    elif track_duration > t_delta:
+        result_matrix = track_arrays[:t_delta, :]
+    else:
+        result_matrix = track_arrays
+    
         
-    flattened_array = track_arrays.flatten()
+    flattened_array = result_matrix.flatten()
         
     return flattened_array