推荐系统评测指标之RMSE、MSE

# -*- coding:utf-8 -*-
from loadMovieLens import *
import math
'''
评测指标
RMSE:均方根误差
MAE:平均绝对误差
'''
def getRMSE(prefer1,prefer2):
rmse = 0
for key1,value in prefer1.items():
zonghe = 0
#迭代测试集，并与结果集进行比较
for key,value in prefer1[key1].items():
temp = pow(value - prefer2[key1][key],2)#算两点的平方
zonghe += temp
rmse += math.sqrt(zonghe)/len(prefer1[key1])
return rmse/len(prefer1)
def getMSE(prefer1,prefer2):
mse = 0
for key1,value in prefer1.items():
zonghe = 0
#迭代测试集，并与结果集进行比较
for key,value in prefer1[key1].items():
temp = abs(value - prefer2[key1][key])#计算两点之间的绝对值
zonghe += temp
mse += zonghe/float(len(prefer1[key1]))
return mse/float(len(prefer1))
if __name__=='__main__':
prefer1 = loadMovieLensTest()
prefer2 = loadResult("D:/数据集/movieLens/result.txt")
#print getRMSE(prefer1,prefer2)
print len(prefer1)
print getMSE(prefer1,prefer2)