' X) x9 _+ ~( q5 `! j" D- D; R# / E( ?& ~1 v8 M5 }: [' j% H- o# 使用 |A&B|/sqrt(|A || B |)计算余弦距离! N* n6 q J6 f. ^/ Y2 Z; K" n
#8 B4 z7 T# ?# ]0 k
# + N1 W( y! l; L% d) C# 0 [' L+ u& X: W$ zdef calcCosDistSpe(user1,user2):# F8 W: d3 M3 ~6 e3 x/ U; u) N
avg_x=0.0 * b- J3 P# |+ o6 g9 i2 o avg_y=0.0+ n' D+ S; d/ z) c* N! h
for key in user1:1 P2 K4 E' N/ C, e1 q. t1 {3 c' g
avg_x+=key[1] - i" K* ~- z @( _1 w ^ avg_x=avg_x/len(user1) ; f* m) i+ C" F' V 8 V7 p; X5 V, ~! P for key in user2:& Z# |; _9 |: `2 ^# k& M
avg_y+=key[1]% o9 k) F _! n' A$ w! D8 m* C8 X) j) O# R
avg_y=avg_y/len(user2)7 I4 L& k: m! U8 b
. e# |- }- ~- H6 d& ~$ @% \ u1_u2=0.0$ h8 }) D# w$ k) R
for key1 in user1: " u& A5 ]$ h+ I& C1 G for key2 in user2:4 I+ v( j' n9 l- h) a8 d
if key1[1] > avg_x and key2[1]>avg_y and key1[0]==key2[0]: % v7 f, L( K- A; X! k; a( \ u1_u2+=1 6 f+ M9 B! j0 w- e& { u1u2=len(user1)*len(user2)*1.0. _+ C0 d/ K7 V( ]* C
sx_sy=u1_u2/math.sqrt(u1u2)6 d) A% r5 t: L/ j
return sx_sy, i: Q& @2 y* s
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0 T/ F, F% l8 r' K/ W5 a0 R# 8 R. k, _# R9 O6 i2 ?# 计算余弦距离7 O: m/ O& s9 ]$ ]
# 4 ^6 G0 j q y; G#6 S4 T$ f5 R4 N9 N
def calcCosDist(user1,user2):( a1 e0 {$ u7 ]3 _# J
sum_x=0.0 % t( n% |$ h3 \( H3 D sum_y=0.0 6 j# _8 A5 `+ }' m" S6 ?9 } sum_xy=0.0* q0 T4 S' h5 I4 n- Z
for key1 in user1: ( P" Y4 t7 Z# w/ ]. U: W4 e9 C for key2 in user2: " Y4 [: A3 V7 ?' F if key1[0]==key2[0] : - w Y& B9 L! s3 q; W sum_xy+=key1[1]*key2[1]6 j' C8 b5 d( W C# \! O- _
sum_y+=key2[1]*key2[1] n5 {% s' p- D4 g' H
sum_x+=key1[1]*key1[1] ; z6 u7 M% Q. P" j$ d/ H2 M( W ' j! `/ @ L: ], B1 d) ~0 d( v
if sum_xy == 0.0 : & X+ L# w6 G4 N: m+ M' }0 i return 0 ) |" E q# L3 D( E! V sx_sy=math.sqrt(sum_x*sum_y) % q2 \1 H5 Y, [- u5 z
return sum_xy/sx_sy# {) L1 d/ P! y4 n8 ~
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$ _: G3 N3 M% L8 q f" n2 j#6 X2 o8 W% f# Z+ |( b0 f
# & `8 ?$ v4 S" T- {# S# 相似余弦距离- s7 r; e @0 T* O1 f% \
# ; _* C* |9 e7 j$ j) y( \#* o& k$ p& z" W7 A
# - p3 ?6 Q# C# _& t5 ?def calcSimlaryCosDist(user1,user2): % }! S+ P& e, P3 D' o8 x sum_x=0.0 " N Z9 y |% u6 K1 D* Q' ]# J sum_y=0.04 c) r5 O: D5 i
sum_xy=0.0 % X$ @' P" C8 V1 A( Q avg_x=0.0$ t; Z& y0 F- Q+ h+ G
avg_y=0.0 ' l0 S5 H2 Y% | for key in user1:# G! n6 o0 E( p6 u. t. ]
avg_x+=key[1]* L) F" C: l6 ]
avg_x=avg_x/len(user1) # ?8 M- @9 `" a$ c: J 9 r& q5 y# S0 g1 C; D" b8 E" F
for key in user2:" L6 P I- p" s8 r2 ]: j; Y
avg_y+=key[1] 9 h$ Q& M& ?2 p | avg_y=avg_y/len(user2)0 k# r* h1 }3 q& ^; E
5 `# t+ r% |5 }; [! j( Q
for key1 in user1:7 Q; ^9 V1 b% v# {1 R5 m0 d
for key2 in user2: 5 m \* Y9 q) j1 ]9 q if key1[0]==key2[0] : f- u6 Q4 R% x sum_xy+=(key1[1]-avg_x)*(key2[1]-avg_y)$ E4 V" X$ s7 N
sum_y+=(key2[1]-avg_y)*(key2[1]-avg_y). D9 H, ^! j) S+ K- Z
sum_x+=(key1[1]-avg_x)*(key1[1]-avg_x) " ^) b+ \/ ` `( O8 Z# `/ n / k. g* q9 L. I if sum_xy == 0.0 :8 n/ L2 f/ k- Y
return 0" d! w; O3 m. v6 }
sx_sy=math.sqrt(sum_x*sum_y) & y n( B5 ^0 I# A" L7 ]* P
return sum_xy/sx_sy7 E" |2 V9 [3 H
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# 读取文件 2 l9 R! i# H7 {( b" M. D* B$ [# ) m' b; i; t% c1 @" n8 l4 ~#' ~6 u* x* ?1 [/ O1 t
def readFile(file_name):$ P1 L( e# U d- m0 A& x
contents_lines=[]; Q* w+ b: T* [2 i/ a" t
f=open(file_name,"r")1 |; y* J8 I4 B1 K* b. K/ X
contents_lines=f.readlines()% o$ f( i' ]% U5 \' z( x. G; v
f.close()- |0 Z7 J9 }8 Z
return contents_lines7 P3 w3 k7 C6 ~/ `) b, A: h
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# 解压rating信息,格式:用户id\t硬盘id\t用户rating\t时间3 W6 ?% f, U( h5 `
# 输入:数据集合 + S- G$ N/ `) I2 u$ B# k# 输出:已经解压的排名信息 6 P' z1 B' \% o" [0 d#7 {* E6 [; d$ |0 t0 h
def getRatingInformation(ratings): 0 h6 R* w! ^2 ~/ ?" t rates=[]% k w" g0 X9 v8 Y/ o2 k( c
for line in ratings:5 i2 t/ @5 X! P" K- E, v5 d
rate=line.split("\t") ' \6 Z7 }8 v6 O/ d# i& Z rates.append([int(rate[0]),int(rate[1]),int(rate[2])])! S3 b* T4 ^: U, Q+ w1 O
return rates . b- [5 e* F4 ~6 ?, {; v& j& b( l' O, h0 }
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# , y0 N4 \, L! n' G$ R6 E# 生成用户评分的数据结构/ R6 T8 X& R2 Y
# ( ~6 h$ C7 h& K9 o# 输入:所以数据 [[2,1,5],[2,4,2]...] / `0 f, p% Z& b; z# 输出:1.用户打分字典 2.电影字典9 F* A$ l% ~3 _9 Y% V
# 使用字典,key是用户id,value是用户对电影的评价, / M. M6 s) T5 m1 L# z- ?# rate_dic[2]=[(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 / ]' S6 s$ F, e# i8 J8 N- `/ C9 N- j; Udef createUserRankDic(rates): + e: A2 u9 h% n user_rate_dic={} # I- ^7 C h; e' Q1 V item_to_user={} ( g! b3 d" T7 {+ L t for i in rates: : ^% Q& {! O1 P* S& z+ ^- x9 | user_rank=(i[1],i[2]) / g+ l4 w6 J; H if i[0] in user_rate_dic: * ^# k: W6 R4 ]$ A6 Z0 P7 u4 I user_rate_dic[i[0]].append(user_rank) ' y$ |, I6 Z& n+ C o) | else:2 P. A) I% P% \7 X2 n" j6 `" A
user_rate_dic[i[0]]=[user_rank] . ?" Q$ V! R1 ^ T4 K# L( V" v: @( N$ ? if i[1] in item_to_user:4 I9 \- N" w- h- @" D
item_to_user[i[1]].append(i[0])4 e" @7 s7 Q, t
else:( ~; ]% q9 u/ G; q) C
item_to_user[i[1]]=[i[0]]# z: l+ D6 y, w' |/ X+ y4 C5 g
3 X P$ ~% y4 }2 i% T return user_rate_dic,item_to_user 8 }# t7 l7 Y4 q8 p6 f k: t/ u- O m
8 g; f' j. f8 t3 l3 N, {#; V3 }5 F; y$ p8 W5 m3 r* f
# 计算与指定用户最相近的邻居2 F9 Q* Y7 u2 e$ Z3 a
# 输入:指定用户ID,所以用户数据,所以物品数据$ O: |( z9 ^( W; \: h* t
# 输出:与指定用户最相邻的邻居列表 ( X+ |0 o' V( H' a# * ?: k+ m4 K% H5 E! Qdef calcNearestNeighbor(userid,users_dic,item_dic): 2 Z8 { N2 F4 S0 S. f neighbors=[]: E2 v" ?. l+ i! l: s/ L" X' E0 F
#neighbors.append(userid) ! q8 S G* f0 C) l. a; b% W for item in users_dic[userid]: ( q* g U8 ~$ V! f9 F for neighbor in item_dic[item[0]]:3 u8 w4 E2 a5 f- o0 S G* ]+ t. `
if neighbor != userid and neighbor not in neighbors: ' ^+ `- f# B# ~( |: G# z S neighbors.append(neighbor)' n# `- g+ I( h
8 x1 d( `. d, A2 L; D3 |! C neighbors_dist=[]7 R# J6 V; m' m6 T$ V0 E1 i
for neighbor in neighbors:8 [2 o7 }& }. u* ^: {
dist=calcSimlaryCosDist(users_dic[userid],users_dic[neighbor]) #calcSimlaryCosDist calcCosDist calcCosDistSpe+ N6 ]# M3 K/ c- U: \1 e7 h
neighbors_dist.append([dist,neighbor]) % K# S. P* u# o' D neighbors_dist.sort(reverse=True): @" T) I8 K& ~5 x2 [7 _6 @2 _* x. x
#print neighbors_dist7 `# p& r6 K, v4 E7 V6 B
return neighbors_dist+ R3 I I2 W, g& b2 F! C2 h
8 O0 m6 h- z* T) m$ t" o; F. V" x) V % [7 o/ X1 C- I# 3 H: S* G# s' M) D8 i/ h# 使用UserFC进行推荐 & y! ~1 \2 E0 s* l( L0 U; U9 A/ t# 输入:文件名,用户ID,邻居数量8 Y( B( u% y) ?) I1 ~# z" k, i
# 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 1 D8 w# W. v$ |9 y4 I# . D% [1 @ [/ l Vdef recommendByUserFC(file_name,userid,k=5): " P& U# Q2 L' ?. Y# F7 A) ] 4 L5 j' o4 D& \" s2 n4 L #读取文件数据6 S5 @4 {8 G# T" Z
test_contents=readFile(file_name)8 O( s2 K/ y! n+ H4 D# x6 Z
9 s- s+ D" l. C, p! x& w6 g
#文件数据格式化成二维数组 List[[用户id,电影id,电影评分]...] " \! K ~. E. F6 X: Z& {: K0 r test_rates=getRatingInformation(test_contents) A- S; N3 |6 Y6 J e, A
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#格式化成字典数据 , @2 i, m' b. C, ~2 f( n# l
# 1.用户字典:dic[用户id]=[(电影id,电影评分)...] " ]8 V$ P7 }4 k& ]5 Z # 2.电影字典:dic[电影id]=[用户id1,用户id2...] - @% P9 @# _* O& M- [' v) r* t: i4 _ test_dic,test_item_to_user=createUserRankDic(test_rates) ; O! k/ c$ K$ K 6 X7 S7 e7 ?9 y
#寻找邻居 - u$ f# t: d" G) x3 x neighbors=calcNearestNeighbor(userid,test_dic,test_item_to_user)[:k]( Y+ I/ e. R8 E) Y7 I) b
/ E: t& G$ _* x+ {% D recommend_dic={} . |& E K) u- h B3 k for neighbor in neighbors:& {4 C& J6 R2 V, e ]! @
neighbor_user_id=neighbor[1] # f: {" ?: K# c movies=test_dic[neighbor_user_id] 0 z+ ~$ _1 }* h6 N0 z1 | for movie in movies: : q$ F+ X2 j1 M+ y1 P% y #print movie - L5 [0 _5 \9 Q2 m if movie[0] not in recommend_dic:: V# a F- J; j) h: _. E3 t
recommend_dic[movie[0]]=neighbor[0]5 d6 X& ^/ j3 z: y
else:7 s T0 x0 m i4 c- c' P6 g7 w
recommend_dic[movie[0]]+=neighbor[0]3 g$ t# Z" z; X" P5 `
#print len(recommend_dic)9 [( p; O# ^1 h' [7 E8 m: a" Z8 {
. @2 L1 Q0 j" x& }; F. M3 z ~. z #建立推荐列表. x5 G0 ~4 ]5 y
recommend_list=[] * j ~- y! j7 b- R- a: P0 u for key in recommend_dic: $ J! |1 j$ c% |: n #print key6 ]' U8 G: X7 Y3 ]- L8 n
recommend_list.append([recommend_dic[key],key])+ ~2 n& w/ R) Q: F, M/ A- X9 m2 @
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recommend_list.sort(reverse=True)6 d( t% H5 q( N" d' B
#print recommend_list: o( E8 h/ v {7 s p
user_movies = [ i[0] for i in test_dic[userid]]( C% j& Q1 w7 I0 }$ p
1 ~7 O$ R% C5 |+ t return [i[1] for i in recommend_list],user_movies,test_item_to_user,neighbors, j7 r/ \3 A/ S
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) N+ Q+ N( M' d D#6 E/ Y! Z" A: Y
# # D0 Y/ @' B( n" [, K+ z# 获取电影的列表 * x3 D/ ^& `( D4 \: q4 b& z# 5 {& y+ y- p: r8 _5 [! ~, M# 9 I% s q4 U8 S- ~# 7 a# N; {2 Q+ p: ydef getMoviesList(file_name): / F6 S# @; w- I& \" d( \7 D" ? #print sys.getdefaultencoding()" m- c1 h% Q7 c& I. A9 b: w! p' A
movies_contents=readFile(file_name) : R G1 [4 {) }, d/ { movies_info={} ( ?" m I$ l, |; X) n for movie in movies_contents: 6 G2 K- w9 }1 S movie_info=movie.split("|")8 y" L+ n- Q" b# X. {1 z' y2 Z! @
movies_info[int(movie_info[0])]=movie_info[1:] ( {0 r9 ~ E3 g2 s& [4 m- ~ return movies_info * L ]9 Q. l* Z+ i2 u( P 2 y9 u- o9 i4 C9 D' [! s( `, }7 v
# r7 a$ v" m4 _ * q; z3 C! D$ v( c4 w1 B#主程序 # t( h1 \7 o! p4 r, G9 @#输入 : 测试数据集合; a" l& d5 C' {- [
if __name__ == '__main__': 7 I) C; S& ^( o reload(sys)) ?; C9 H& M9 [. |6 J( g
sys.setdefaultencoding('utf-8')5 k) X) U; U( w4 [: S8 s7 V6 p2 m
movies=getMoviesList("/Users/wuyinghao/Downloads/ml-100k/u.item")% A& q) b/ l% `, }
recommend_list,user_movie,items_movie,neighbors=recommendByUserFC("/Users/wuyinghao/Downloads/ml-100k/u.data",179,80) + J0 X- r6 Q( ?) ^+ t neighbors_id=[ i[1] for i in neighbors] 7 v& O' _- a+ F. ?, q% \ table = Texttable(); [7 t: Y$ `8 R
table.set_deco(Texttable.HEADER) . w5 |: L9 G, r% }6 Z3 u. W table.set_cols_dtype(['t', # text + v- R! n6 H0 b2 S& u8 q; U$ H* v4 I 't', # float (decimal) N' Q1 p: j/ d8 z: o4 A2 ]
't']) # automatic; s" z2 R2 `1 ~( v5 C& t8 w% L8 F
table.set_cols_align(["l", "l", "l"])4 L) F/ }, v6 j/ Q4 K
rows=[] ' j6 Z! z/ K, J. C# J rows.append([u"movie name",u"release", u"from userid"]) $ ^' V- y' X; J3 Z) ?% a2 D for movie_id in recommend_list[:20]: ' X" U! E2 c+ x/ w, x from_user=[] 3 h( K* b: E, W2 D for user_id in items_movie[movie_id]:8 I3 j! M% f: H: e$ {3 }
if user_id in neighbors_id: ) B. L, Y; a5 u$ q" s" ~ from_user.append(user_id)" e ^7 D% J# e- p2 w. p2 S6 x2 l
rows.append([movies[movie_id][0],movies[movie_id][1],""]) 6 q& k2 E0 j8 U table.add_rows(rows)7 F! E! q( b) p3 [* G, y
print table.draw()作者: mea_lsc 时间: 2015-4-19 00:25
百年孤独 发表于 2014-7-19 09:22 9 i) l% P" K0 d7 N: D. b
# -*- coding=utf-8 -*-( P1 S4 G* r1 u% o) _, C9 b) ~
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import math