在Python中，将矩阵的列乘以不同的数字

Question

我有一个脚本中的矩阵hsa。现在我想用numpy将它的第一列乘以sqrt（2），第二列乘以sqrt（2），第三列乘以1来创建一个结果矩阵HSA（预期）？我使用了给定的代码，但它不起作用

import pandas as pd import numpy as np import math hs = np.loadtxt('HS', skiprows=8) from itertools import islice with open('HS') as lines: array = np.genfromtxt(islice(lines, 2, 5)) lv=np.diag(array) hsa=hs*lv print (hsa) HSA= [sqrt(2)*hsa(:,1), sqrt(2)*hsa(:,2), 1*hsa(:,1)] print (HSA) hsa= [[1 0 5] [1 0 7] [1 0 9] [1 0 5] [1 0 6] [1 0 4] [1 0 5] [0 1 6] [0 1 1] [0 1 7] [0 1 3] [0 1 3] [0 1 5]] (Expected) HSA= [[1.414 0 5] [1.414 0 7] [1.414 0 9] [1.414 0 5] [1.414 0 6] [1.414 0 4] [1.414 0 5] [0 1.414 6] [0 1.414 1] [0 1.414 7] [0 1.414 3] [0 1.414 3] [0 1.414 5]]

Answer 1

Numpy可以直接在第一个维度上广播：

HSA = hsa * np.array([np.sqrt(2.), np.sqrt(2.), 1])