numpy矩阵基本操作总结

import numpy as np;import math;#构造矩阵m = np.mat([[1,2,3,4],[2,2,3,4],[3,2,3,4],[4,2,3,4]]);print(m);#取第i行,从0开始计数row1 = m[0];print(row1);#取[i,j]元素,从0开始计数,如果是：这种形式那么是从i开始包含i,到j截至不包含jitem1 = m[0, 1];print(item1);item2 = m[0, :];print(item2);item3 = m[0:2, 0:3];print(item3);#矩阵运算n = np.mat([[5,5,5,5],[2,2,2,2]]);result = m * n.transpose();print(result);addRes = m + m;print(addRes);subRes = m - m;print(subRes);powRes = np.power(m, 2);print(powRes);logRes = np.log(m);print(logRes);#求矩阵的行数和列数rowM, colM = np.shape(m);rowN = np.shape(n)[0];colN = np.shape(n)[1];print(rowN, colN);zeros = np.zeros((4, 3));print(zeros);ones = np.ones((4, 3));print(ones);constantMat = np.full((4, 3), 7);print(constantMat);#创建单位矩阵I = np.eye(2);print(I);#输出随机元素构成的矩阵randomMat = np.random.random((2, 3));print(randomMat);#矩阵拼接按行拼接row_stack,和按列拼接column_stackmn = np.row_stack((m, n));print(mn);