diff --git a/Analysis/report_graph.py b/Analysis/report_graph.py
index 33dd796b4a61f6c781db2b58b539c1fcd4305dc2..38de2e5bf832f624c4024a85e3f96166afad3669 100755
--- a/Analysis/report_graph.py
+++ b/Analysis/report_graph.py
@@ -11,6 +11,8 @@ from networkx import nx_agraph
 import os
 
 def read_eddy_graph(edgelist, shp_tr_dir = None, read_interp = True):
+    """shp_tr_dir is for visible eddies."""
+
     G = nx.DiGraph()
 
     if os.access(edgelist, os.R_OK):
@@ -37,8 +39,8 @@ def read_eddy_graph(edgelist, shp_tr_dir = None, read_interp = True):
 
             # Assuming that the directory containing the interpolated
             # eddies is in the same location as edgelist:
-            extr_file = path.join(path.dirname(edgelist), "SHP_triplet",
-                                 "extremum.shp")
+            dir_edgelist = path.dirname(edgelist)
+            extr_file = path.join(dir_edgelist, "SHP_triplet", "extremum.shp")
 
             if os.access(extr_file, os.R_OK):
                 set_attribute(G, extr_file)
@@ -59,6 +61,7 @@ def set_attribute(G, extr_file):
     with shapefile.Reader(extr_file) as s_read:
         for shape_rec in s_read:
             n = (shape_rec.record.days_1950, shape_rec.record.eddy_index)
+            
             if (shape_rec.record.valid == 1
                 or shape_rec.record.interpolat == 1) and n in G:
                 G.add_node(n,
@@ -76,7 +79,7 @@ def to_eddy_agraph(G):
 
     A = nx_agraph.to_agraph(G)
 
-    for k, s in my_subgraphs.items():
+    for d, s in my_subgraphs.items():
         A.add_subgraph(s, rank = "same")
 
     for n in G: