求协同过滤算法程序
本人在学校参加暑假培训，需要这个算法做题！求大神赐教，感激不尽# -*- coding=utf-8 -*-
import math
import sys
from texttable import Texttable
#
# 使用 |A&B|/sqrt(|A || B |)计算余弦距离
#
#
#
def calcCosDistSpe(user1,user2):
avg_x=0.0
avg_y=0.0
for key in user1:
avg_x+=key
avg_x=avg_x/len(user1)
for key in user2:
avg_y+=key
avg_y=avg_y/len(user2)
u1_u2=0.0
for key1 in user1:
for key2 in user2:
if key1 > avg_x and key2>avg_y and key1==key2:
u1_u2+=1
u1u2=len(user1)*len(user2)*1.0
sx_sy=u1_u2/math.sqrt(u1u2)
return sx_sy
#
# 计算余弦距离
#
#
def calcCosDist(user1,user2):
sum_x=0.0
sum_y=0.0
sum_xy=0.0
for key1 in user1:
for key2 in user2:
if key1==key2 :
sum_xy+=key1*key2
sum_y+=key2*key2
sum_x+=key1*key1
if sum_xy == 0.0 :
return 0
sx_sy=math.sqrt(sum_x*sum_y)
return sum_xy/sx_sy
#
#
# 相似余弦距离
#
#
#
def calcSimlaryCosDist(user1,user2):
sum_x=0.0
sum_y=0.0
sum_xy=0.0
avg_x=0.0
avg_y=0.0
for key in user1:
avg_x+=key
avg_x=avg_x/len(user1)
for key in user2:
avg_y+=key
avg_y=avg_y/len(user2)
for key1 in user1:
for key2 in user2:
if key1==key2 :
sum_xy+=(key1-avg_x)*(key2-avg_y)
sum_y+=(key2-avg_y)*(key2-avg_y)
sum_x+=(key1-avg_x)*(key1-avg_x)
if sum_xy == 0.0 :
return 0
sx_sy=math.sqrt(sum_x*sum_y)
return sum_xy/sx_sy
#
# 读取文件
#
#
def readFile(file_name):
contents_lines=[]
f=open(file_name,"r")
contents_lines=f.readlines()
f.close()
return contents_lines
#
# 解压rating信息，格式：用户id\t硬盘id\t用户rating\t时间
# 输入：数据集合
# 输出:已经解压的排名信息
#
def getRatingInformation(ratings):
rates=[]
for line in ratings:
rate=line.split("\t")
rates.append(),int(rate),int(rate)])
return rates
#
# 生成用户评分的数据结构
#
# 输入:所以数据 [,...]
# 输出:1.用户打分字典 2.电影字典
# 使用字典，key是用户id，value是用户对电影的评价，
# rate_dic=[(1,5),(4,2)].... 表示用户2对电影1的评分是5，对电影4的评分是2
#
def createUserRankDic(rates):
user_rate_dic={}
item_to_user={}
for i in rates:
user_rank=(i,i)
if i in user_rate_dic:
user_rate_dic].append(user_rank)
else:
user_rate_dic]=
if i in item_to_user:
item_to_user].append(i)
else:
item_to_user]=]
return user_rate_dic,item_to_user
#
# 计算与指定用户最相近的邻居
# 输入:指定用户ID，所以用户数据，所以物品数据
# 输出:与指定用户最相邻的邻居列表
#
def calcNearestNeighbor(userid,users_dic,item_dic):
neighbors=[]
#neighbors.append(userid)
for item in users_dic:
for neighbor in item_dic]:
if neighbor != userid and neighbor not in neighbors:
neighbors.append(neighbor)
neighbors_dist=[]
for neighbor in neighbors:
dist=calcSimlaryCosDist(users_dic,users_dic) #calcSimlaryCosDist calcCosDist calcCosDistSpe
neighbors_dist.append()
neighbors_dist.sort(reverse=True)
#print neighbors_dist
return neighbors_dist
#
# 使用UserFC进行推荐
# 输入：文件名,用户ID,邻居数量
# 输出：推荐的电影ID,输入用户的电影列表,电影对应用户的反序表，邻居列表
#
def recommendByUserFC(file_name,userid,k=5):
#读取文件数据
test_contents=readFile(file_name)
#文件数据格式化成二维数组 List[[用户id,电影id,电影评分]...]
test_rates=getRatingInformation(test_contents)
#格式化成字典数据
# 1.用户字典：dic[用户id]=[(电影id,电影评分)...]
# 2.电影字典：dic[电影id]=[用户id1,用户id2...]
test_dic,test_item_to_user=createUserRankDic(test_rates)
#寻找邻居
neighbors=calcNearestNeighbor(userid,test_dic,test_item_to_user)[:k]
recommend_dic={}
for neighbor in neighbors:
neighbor_user_id=neighbor
movies=test_dic
for movie in movies:
#print movie
if movie not in recommend_dic:
recommend_dic]=neighbor
else:
recommend_dic]+=neighbor
#print len(recommend_dic)
#建立推荐列表
recommend_list=[]
for key in recommend_dic:
#print key
recommend_list.append(,key])
recommend_list.sort(reverse=True)
#print recommend_list
user_movies = [ i for i in test_dic]
return for i in recommend_list],user_movies,test_item_to_user,neighbors
#
#
# 获取电影的列表
#
#
#
def getMoviesList(file_name):
#print sys.getdefaultencoding()
movies_contents=readFile(file_name)
movies_info={}
for movie in movies_contents:
movie_info=movie.split("|")
movies_info)]=movie_info
return movies_info
#主程序
#输入 ： 测试数据集合
if __name__ == '__main__':
reload(sys)
sys.setdefaultencoding('utf-8')
movies=getMoviesList("/Users/wuyinghao/Downloads/ml-100k/u.item")
recommend_list,user_movie,items_movie,neighbors=recommendByUserFC("/Users/wuyinghao/Downloads/ml-100k/u.data",179,80)
neighbors_id=[ i for i in neighbors]
table = Texttable()
table.set_deco(Texttable.HEADER)
table.set_cols_dtype(['t', # text
't', # float (decimal)
't']) # automatic
table.set_cols_align(["l", "l", "l"])
rows=[]
rows.append()
for movie_id in recommend_list[:20]:
from_user=[]
for user_id in items_movie:
if user_id in neighbors_id:
from_user.append(user_id)
rows.append(,movies,""])
table.add_rows(rows)
print table.draw() 百年孤独 发表于 2014-7-19 09:22 static/image/common/back.gif
# -*- coding=utf-8 -*-
import math
这是什么语言的程序？
我来水帖攒体力了，哈哈哈哈哈哈哈哈哈哈哈哈
页:
[1]