计算两个矩阵的余弦相似度

Question

I have defined two matrices like following:

from scipy import linalg, mat, dot
a = mat([-0.711,0.730])
b = mat([-1.099,0.124])

Now, I want to calculate the cosine similarity of these two matrices . What is the wrong with following code. It gives me an error of objects are not aligned

c = dot(a,b)/np.linalg.norm(a)/np.linalg.norm(b)

Answer 1

You cannot multiply 1x2 matrix by 1x2 matrix. In order to calculate dot product between their rows the second one has to be transposed.

from scipy import linalg, mat, dot
a = mat([-0.711,0.730])
b = mat([-1.099,0.124])

c = dot(a,b.T)/linalg.norm(a)/linalg.norm(b)

Answer 2

also:

import numpy as np
import scipy.spatial.distance as distance
a = np.array([0.1, 0.2])
b = np.array([0.3,0.4])
c = 1 - distance.cosine(a, b)

see: https://docs.scipy.org/doc/scipy/reference/generated/scipy.spatial.distance.cosine.html#scipy.spatial.distance.cosine