diff --git a/Convert_Matlab/inst_eddies_v6.py b/Convert_Matlab/inst_eddies_v6.py
index 4fad994aa78986892e5df70c36a2b1e0873ece7a..bbf63ade01de033bc5d67ed1ebfc4ee914fd13bc 100755
--- a/Convert_Matlab/inst_eddies_v6.py
+++ b/Convert_Matlab/inst_eddies_v6.py
@@ -44,9 +44,13 @@ def define_fields(writers):
     writers["max_speed"].field("eddy_index", "N", 5)
 
 def write(writers, cell, cyclone):
-    """writers is a dictionary. cell is a numpy.ndarray with shape (number
-    of eddies, 21). cyclone is a boolean. The eddy identification
-    numbers start at 1 and increment by 1 for each eddy in cell.
+    """Write to shapefiles eddies with a given orientation, at a given
+    date.
+
+    writers is a dictionary. cell is a numpy.ndarray with shape
+    (number of eddies, 21). cyclone is a boolean. The eddy
+    identification numbers start at 1 and increment by 1 for each eddy
+    in cell.
 
     """
     eddy_index = 0
@@ -115,6 +119,7 @@ if len(sys.argv) == 3:
 else:
     final_date = my_date
 
+# There are two factories, one for cyclones and one for anticyclones:
 factories = [dict(writers = {}, cell_name = "Anticyclonic_Cell",
                   cyclone = False, SHPC = "SHPC_anti"),
              dict(writers = {}, cell_name = "Cyclonic_Cell", cyclone = True,
@@ -141,6 +146,7 @@ for f in factories:
     f["writers"]["ishape_last"] = open(file, "w")
     
 
+# Loop on dates:
 while True:
     if os.access(adt_file, os.R_OK):
         print("Processing", my_date, "...")