January 6, 2014 09:40 · Jan 6, 2014
diff --git a/eva.py b/eva.py
@@ -0,0 +1,88 @@
+# !/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import math
+
+def prf(tlist, plist, n):
+    '''
+    cal the (precision, recall, f-score)
+
+    rlist:real values list
+    plist:predicted values list
+    n:compare first n values
+    '''
+
+    if not (tlist and plist):
+        return .0, .0, .0
+
+    tset = set(tlist)
+    pset = set(plist[:n])
+
+    m = float(len(pset.intersection(tset)))
+
+    precision = m/len(pset)
+    recall = m/len(tset)
+    fscore = 2*precision*recall/(precision+recall+0.1)
+
+    return precision, recall, fscore
+
+def ap(tlist, plist, n):
+    '''
+    cal the average precision
+
+    rlist:real values list
+    plist:predicted values list
+    n:compare first n values
+    '''
+    if not (tlist and plist):
+        return .0, .0, .0
+
+    apval = .0
+    last_recall = .0
+    for i in range(n+1)[1:]:
+        if i>len(plist):
+            break
+        precision, recall, _ = prf(tlist, plist, i)
+        apval += precision*(recall-last_recall)
+        last_recall = recall
+
+    return apval
+
+def ndcg(tlist, plist, n):
+    '''
+    cal the ndcg value
+
+    rlist:real values list
+    plist:predicted values list
+    n:compare first n values
+    '''
+    if not (tlist and plist):
+        return .0, .0, .0
+
+    wdict = {}
+    for i in range(len(tlist)):
+        wdict[tlist[i]] = 1.0/(i+1.0)
+    ndcg = .0; ndcgopt = .0
+    for i in range(len(plist[:n])):
+        if plist[i] in wdict:
+            w = wdict[plist[i]]
+        else:
+            w = 1.0/len(tlist)
+
+        ndcg += (pow(2, w)-1)/math.log(i+2, 2)
+        ndcgopt += (pow(2, 1.0/(i+1.0))-1)/math.log(i+2, 2)
+
+    return ndcg / ndcgopt
+
+
+
+
+if __name__ == '__main__':
+    tlist = [1,2,3,4, 5]
+    plist = [4,1, 2,5,3]
+
+    for n in [1,2,3,4, 5]:
+        print '\n', n
+        print prf(tlist, plist, n)
+        print ap(tlist, plist, n)
+        print ndcg(tlist, plist, n)