diff --git a/Analysis/plot_traj.py b/Analysis/plot_traj.py
index 3039f4a4467dc532f0def7ca7163314590ca6954..9119cd8f06a85ff4c4ea6eafda4efdf5d3044307 100755
--- a/Analysis/plot_traj.py
+++ b/Analysis/plot_traj.py
@@ -19,9 +19,9 @@ def compute_ishape(n, k1, ishape_last):
     else:
         return ishape
 
-def get_coord(n, k1, ishape_last, sr):
+def get_coord(n, k1, ishape_last, s_read):
     ishape = compute_ishape(n, k1, ishape_last)
-    return sr.shape(ishape).points[0]
+    return s_read.shape(ishape).points[0]
 
 if __name__ == "__main__":
     import itertools
@@ -39,9 +39,9 @@ if __name__ == "__main__":
                              dtype = int)
     pos = {}
     
-    with shapefile.Reader(path.join(shp_tr_dir, "extremum")) as sr:
-        k1 = sr.record(0)["date_index"]
-        for n in G: pos[n] = get_coord(n, k1, ishape_last, sr)
+    with shapefile.Reader(path.join(shp_tr_dir, "extremum")) as s_read:
+        k1 = s_read.record(0)["date_index"]
+        for n in G: pos[n] = get_coord(n, k1, ishape_last, s_read)
 
     color_iter = itertools.cycle(('#1f77b4', '#aec7e8', '#ff7f0e', '#ffbb78',
                                   '#2ca02c', '#98df8a', '#d62728', '#ff9896',