add graph diff

pyHON/graph-diff.py

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+# computes diff of neighboring static graphs of a dynamic graph,
+# and plot the diff scores
+
+# Note: this file (implements the weight difference)
+# serves as an example of how graph differences can be computed.
+# Network differences can be computed in many other ways (max common subgraph, etc)
+# The code won't run out of the box (it was written a long time ago; some paths need to be updated).
+# Still, hope this snippet can be helpful.
+
+import matplotlib.pyplot as plt
+import glob
+import pprint
+import datetime
+
+filetype = 'bayesian-firstorder-10'
+k = 7
+NoWeekends = False
+
+NetworkPath = '../data/NYC-' + filetype + '-network/*'
+filetype = filetype + '-k' + str(k)
+if NoWeekends:
+    filetype = filetype + '-NoWeekends'
+
+
+fn = glob.glob(NetworkPath)
+fncleaned = []
+if NoWeekends:
+    for f in fn:
+        date = f.strip().split('\\')[-1].split('.')[0]
+        month, day = date.split('_')
+        time = datetime.date(2013, int(month), int(day))
+        if time.isoweekday() < 6:
+            fncleaned.append(f)
+    fn = fncleaned[:]
+fn = sorted(fn)
+print(fn)
+pairs = list(zip(fn[:-k], fn[k:]))
+distances = []
+
+
+for pair in pairs:
+    fileG = pair[0]
+    fileH = pair[1]
+    print(fileG)
+    distance = 0
+    AllEdges = set()
+    GEdges = {}
+    HEdges = {}
+    GEdgesSet = set()
+    HEdgesSet = set()
+    VerboseDistances = []
+    with open(fileG) as FG:
+        with open(fileH) as FH:
+            for line in FG:
+                fields = line.split(',')
+                FromNode = fields[0]
+                ToNode = fields[1]
+                weight = float(fields[2].strip())
+                GEdges[(FromNode, ToNode)] = weight
+                GEdgesSet.add((FromNode, ToNode))
+            for line in FH:
+                fields = line.split(',')
+                FromNode = fields[0]
+                ToNode = fields[1]
+                weight = float(fields[2].strip())
+                HEdges[(FromNode, ToNode)] = weight
+                HEdgesSet.add((FromNode, ToNode))
+    # edges as the union of the two graphs
+    AllEdges = GEdgesSet | HEdgesSet
+    for edge in AllEdges:
+        if edge in GEdges:
+            GWeight = GEdges[edge]
+        else:
+            GWeight = 0
+        if edge in HEdges:
+            HWeight = HEdges[edge]
+        else:
+            HWeight = 0
+        #print(GWeight, HWeight, abs(GWeight - HWeight) / max(GWeight, HWeight))
+        value = abs(GWeight - HWeight) / max(GWeight, HWeight)
+        distance += value
+        VerboseDistances.append((value, edge, GWeight, HWeight))
+    distance /= len(AllEdges)
+    distances.append(distance)
+    #pprint.pprint(sorted(VerboseDistances, reverse=True)[:10])
+print(distances)
+#plt.clf()
+plt.plot(distances)
+plt.savefig('../figs/NYC-'+filetype+'.png')
+with open('../data/NYC-'+filetype+'-distances.csv', 'w') as f:
+    for distance in distances:
+        f.write(str(distance) + '\n')