Add argument to read interpolated eddies

Add argument to function `read_eddy_graph` to separately control the
reading and setting of attributes of interpolated eddies.  This is in
preparation for a transfer of this task from the main part of the
script to function `read_eddy_graph`.

Analysis/report_graph.py

@@ -5,7 +5,7 @@ import csv
 import shapefile
 from os import path
 
-def read_eddy_graph(edgelist, shp_tr_dir = None):
+def read_eddy_graph(edgelist, shp_tr_dir = None, read_interp = True):
     G = nx.DiGraph()
 
     with open(edgelist) as f:
@@ -20,10 +20,8 @@ def read_eddy_graph(edgelist, shp_tr_dir = None):
                                      int(row[3]), float(row[4])
             G.add_edge((k1, i1), (k2, i2), weight = weight)
 
-    if shp_tr_dir is not None:
-        # Read attributes of nodes:
-        
-        # Interpolated eddies:
+    if read_interp:
+        # Read and set attributes of interpolated eddies:
 
         # Assuming that the directory containing the interpolated
         # eddies is in the same location as edgelist:
@@ -37,7 +35,8 @@ def read_eddy_graph(edgelist, shp_tr_dir = None):
                            interpolat = True, speed = shape_rec.record.speed,
                            ssh = shape_rec.record.ssh)
 
-        # Visible eddies:
+    if shp_tr_dir is not None:
+        # Read and set attributes of Visible eddies:
         
         extremum = path.join(shp_tr_dir, "extremum")
 
@@ -74,7 +73,7 @@ if __name__ == "__main__":
                         type = int, metavar = ("date_index", "eddy_index"))
     args = parser.parse_args()
     
-    G = read_eddy_graph("edgelist.csv")
+    G = read_eddy_graph("edgelist.csv", read_interp = False)
 
     if args.node is None:
         H = G