diff --git a/Convert_Matlab/overlap_v6.py b/Convert_Matlab/overlap_v6.py
index 9d0234ec33c7c2182935d7cd8ec342da4007d863..d8cdaaf67d53f297d9327827022062caeced8c2a 100755
--- a/Convert_Matlab/overlap_v6.py
+++ b/Convert_Matlab/overlap_v6.py
@@ -10,12 +10,7 @@ import datetime
 import csv
 import sys
 
-def convert_id(cyclone, node_index):
-
-    We assume that the shapefiles are created by the script
-    "mat_to_shapefiles.py", that is: at each date, all the
-    anticyclones are before all the cyclones. We use global variable
-    Nanti.
+def convert_id(node_index):
     """Convert from node identification in graph to eddy identification in
     shapefiles.
 
@@ -24,17 +19,12 @@ def convert_id(cyclone, node_index):
     date = datetime.date.fromordinal(date_num[k] - 366) - datetime.date(1950,
                                                                         1, 1)
     date = date.days
-    
-    if cyclone:
-        eddy_index_F = Nanti[k] + node_index - k * n_max
-    else:
-        eddy_index_F = node_index - k * n_max
-
-    return date, eddy_index_F
+    eddy_index = node_index - k * n_max
+    return date, eddy_index
 
-def print_edgelist(id_child, cyclone):
+def print_edgelist(id_child):
     for i1, id_child_1 in enumerate(id_child):
-        predecessor = (cyclone, k1 * n_max + 1 + i1)
+        predecessor = k1 * n_max + 1 + i1
         # id_child_1 may be an int, which means there is a single
         # successor, or id_child_1 may be a numpy array, which means
         # there are several successors.
@@ -42,26 +32,23 @@ def print_edgelist(id_child, cyclone):
         try:
             # Try processing id_child_1 as an array:
             for node_index in id_child_1:
-                writer.writerow(convert_id(*predecessor)
-                                + convert_id(cyclone, node_index))
+                writer.writerow(convert_id(predecessor)
+                                + convert_id(node_index))
         except TypeError:
             # id_child_1 is a scalar int.
-            writer.writerow(convert_id(*predecessor)
-                            + convert_id(cyclone, id_child_1))
+            writer.writerow(convert_id(predecessor) + convert_id(id_child_1))
 
 orientation = sys.argv[1]
 id_child = sio.loadmat(f"id_child_{orientation}.mat", squeeze_me=True)\
     ["id_child"]
-Nanti = sio.loadmat("Nanti.mat", squeeze_me = True)["Nanti"]\
-           .astype(int, casting = "safe", copy = False)
-cyclone = orientation == "cyclo"
 
-if cyclone:
-    n_eddies = sio.loadmat("Ncyclo.mat", squeeze_me = True)["Ncyclo"]\
-                  .astype(int, casting = "safe", copy = False)
+if orientation == "cyclo":
+    var_name = "Ncyclo"
 else:
-    n_eddies = Nanti
-    
+    var_name = "Nanti"
+
+n_eddies = sio.loadmat(f"{var_name}.mat", squeeze_me = True)[var_name]\
+              .astype(int, casting = "safe", copy = False)
 date_num = sio.loadmat("date_num.mat", squeeze_me = True)["date_num"]
 n_dates = n_eddies.size
 print("n_dates =", n_dates)
@@ -75,4 +62,4 @@ with open(f"edgelist_{orientation}.csv", "w", newline = '') as edgelist:
     writer.writerow(["k1", "i1", "k2", "i2"])
 
     for k1 in range(n_dates):
-        print_edgelist(id_child[:n_eddies[k1], k1], cyclone)
+        print_edgelist(id_child[:n_eddies[k1], k1])
diff --git a/Tests/short_tests.json b/Tests/short_tests.json
index 6ee1e836ca500fa63b7982c6213f96c04b4c6d4d..da1dfcdf36f623a27e1577729525ba3ff321cce1 100644
--- a/Tests/short_tests.json
+++ b/Tests/short_tests.json
@@ -1038,7 +1038,6 @@
 	"required":
 	[
 	    "$src_dir/Tests/Input/Eurec4A_OA/id_child_cyclo.mat",
-	    "$src_dir/Tests/Input/Eurec4A_OA/Nanti.mat",
 	    "$src_dir/Tests/Input/Eurec4A_OA/Ncyclo.mat",
 	    "$src_dir/Tests/Input/Eurec4A_OA/date_num.mat"
 	]