计算两向量的欧式距离，余弦相似度

 

 

 

>>> import numpy >>> vec1=[[1,1,1],[2,2,2]] >>> vec2=[[2,2,2],[1,1,1]] >>> vec1=numpy.array(vec1) >>> vec2=numpy.array(vec2) >>> vec1 array([[1, 1, 1], [2, 2, 2]]) >>> vec2 array([[2, 2, 2], [1, 1, 1]]) >>> dist = numpy.sqrt(numpy.sum(numpy.square(vec1 - vec2))) >>> dist 2.4494897427831779 >>> numpy.linalg.norm(vec1-vec2) 2.4494897427831779

 

 

 

 

余弦相似度：

 

>>> vec1 array([[1, 1, 1], [2, 2, 2]]) >>> vec2 array([[2, 2, 2], [1, 1, 1]]) >>> num=float(numpy.sum(vec1*vec2)) >>> num 12.0 >>> denom=numpy.linalg.norm(vec1)*numpy.linalg.norm(vec2) >>> cos=num/denom >>> denom 15.000000000000002