Question

ur[5][8]=
[[0,3,4,0,0,0,5,0],
[4,5,0,0,0,0,3,0],
[0,4,0,3,0,0,1,4],
[2,0,5,0,0,0,3,0],
[0,0,0,5,0,0,0,4]]

0表示未评级的电影我想用余弦相似度预测每个用户的未评级电影的评级，并且在计算相似度之后我拿起k个最相似的用户并根据那个预测

但如何使用skearn库或任何其他

中的内置函数计算余弦相似度

code:
similar=[[0] * 5 for i in range(5)]
print similar
for x in range(0,5):
    for y in range(0,5):
        similar[x][y] = sklearn.metrics.pairwise.cosine_similarity(ur[x],ur[y])

error :
runfile('C:/Users/Nitin/cf/first.py', wdir='C:/Users/Nitin/cf')
[[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]
Traceback (most recent call last):

  File "<ipython-input-18-e55296403aad>", line 1, in <module>
    runfile('C:/Users/Nitin/cf/first.py', wdir='C:/Users/Nitin/cf')

  File "C:\Users\Nitin\Anaconda2\lib\site-packages\spyder\utils\site\sitecustomize.py", line 880, in runfile
    execfile(filename, namespace)

  File "C:\Users\Nitin\Anaconda2\lib\site-packages\spyder\utils\site\sitecustomize.py", line 87, in execfile
    exec(compile(scripttext, filename, 'exec'), glob, loc)

  File "C:/Users/Nitin/cf/first.py", line 23, in <module>
    similar[x][y] = sklearn.metrics.pairwise.cosine_similarity(ur[x],ur[y])

AttributeError: 'module' object has no attribute 'metrics'

cosine_similarity传递什么或如何正确执行此操作

Answer 1

您需要导入模块才能使用它。

from sklearn.metrics.pairwise import cosine_similarity

OR

import sklearn
# to use it like 
sklearn.metrics.pairwise.cosine_similarity(ur[x],ur[y])

然后使用它。

from sklearn.metrics.pairwise import cosine_similarity

ur = [[0,3,4,0,0,0,5,0],
[4,5,0,0,0,0,3,0],
[0,4,0,3,0,0,1,4],
[2,0,5,0,0,0,3,0],
[0,0,0,5,0,0,0,4]]

similar=[[0] * 5 for i in range(5)]
print(similar)
for x in range(0,5):
    for y in range(0,5):
        similar[x][y] = cosine_similarity(ur[x],ur[y])

similar

输出：

[[array([[ 1.]]),
  array([[ 0.6]]),
  array([[ 0.37097041]]),
  array([[ 0.80295507]]),
  array([[ 0.]])],

sklearn余弦相似性:: AttributeError：'module'对象没有属性'metrics'

1 个答案: