Write `e_overestim` to the graph-tool file

This will much more convenient for `cost_function.py` and
`trajectories.py`. Note we then have to create a file
`e_overestim.txt` for `Trajectories/Tests/edgelist_Isic_[12].csv`.

Trajectories/Tests/e_overestim.txt

+1

Trajectories/segments.py

@@ -15,6 +15,7 @@ import graph_tool
 import time
 import sys
 import pathlib
+from os import path
 
 if len(sys.argv) != 3:
     sys.exit("Required arguments: input-edgelist-file output-graph-tool-file")
@@ -40,6 +41,17 @@ t0 = t1
 
 # Processing:
 
+# e_overestim is not used in this script but it useful to save it to
+# the output graph of this script for further processing of the output
+# graph by other scripts:
+
+g.graph_properties["e_overestim"] = g.new_graph_property("int")
+dir_edgelist = path.dirname(sys.argv[1])
+e_overestim_file = path.join(dir_edgelist, "e_overestim.txt")
+
+with open(e_overestim_file) as f:
+    g.graph_properties["e_overestim"] = int(f.read())
+
 g.vp['inst_eddies'] = g.new_vp('vector<int>')
 for v in g.vertices(): g.vp.inst_eddies[v] = [int(g.vp.name[v])]
 # "inst_eddies" is the list of instantaneous eddies represented by a