【机器学习实战】计算两个矩阵的成对距离(pair-wise distances)
矩阵中每一行是一个样本,计算两个矩阵样本之间的距离,即成对距离(pair-wise distances),可以采用 sklearn 或 scipy 中的函数,方便计算。 sklearn: sklearn.metrics.pairwise_distances scipy: scipy.spatial.distance_matrix (用于 p-norm) 或 scipy.spatial.distance.cdist (所有常用距离 metrics) 比较三者的运行时间:(都计算欧式距离) import numpy as np from sklearn.metrics import pairwise_distances from scipy.spatial import distance_matrix from scipy.spatial.distance import cdist # 10-dimensional features x = np.random.rand(400000).reshape((-1, 10)) y = np.random.rand(45000).reshape((-1, 10)) def option1(): dists = pairwise_distances(x, y) def option2(): dists = distance_matrix(x,