1 files changed, 38 insertions, 0 deletions
diff --git a/gi/evaluation/entropy.py b/gi/evaluation/entropy.py
new file mode 100644
index 00000000..cef0dbb4
--- /dev/null
+++ b/gi/evaluation/entropy.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+
+import sys, math, itertools, getopt
+
+def usage():
+    print >>sys.stderr, 'Usage:', sys.argv[0], '[-s slash_threshold] input file'
+    sys.exit(0)
+
+optlist, args = getopt.getopt(sys.argv[1:], 'hs:')
+slash_threshold = None
+for opt, arg in optlist:
+    if opt == '-s':
+        slash_threshold = int(arg)
+    else:
+        usage()
+if len(args) != 1:
+    usage()
+
+infile = open(args[0])
+N = 0
+frequencies = {}
+
+for line in infile:
+
+    for part in line.split('||| ')[1].split():
+        tag = part.split(':',1)[1]
+
+        if slash_threshold == None or tag.count('/') + tag.count('\\') <= slash_threshold:
+            frequencies.setdefault(gtag, 0)
+            frequencies[gtag] += 1
+            N += 1
+
+h = 0
+for tag, c in frequencies.items():
+    h -= c * (math.log(c, 2) - math.log(N, 2))
+h /= N
+
+print 'entropy', h