spyder
win10
python3
from numpy.linalg import inv,qrgenerate a random matrix of 5 to 5
X = np.random.randn(5,5)first find the transpose of the matrix (.T), and then find the dot product (.dot)
mat = X.T.dot(X)find the inverse of the matrix
inv(mat)get the unit matrix
mat.dot(inv(mat))use QR decomposition to assign values to QMagi R
respectively.q,r = qr(mat) get orthogonal matrix
orthogonal matrix, and the product of matrix and its transpose matrix is E
qget the upper triangular matrix
rE1 = q*(q.T)
E1