# Author: Alex Gezerlis

# Numerical Methods in Physics with Python (CUP, 2020)

from triang import testcreate

from invpowershift import invpowershift

from qrmet import qrmet

import numpy as np

def eig(A,eps=1.e-12):

n = A.shape[0]

eigvals = np.zeros(n)

eigvecs = np.zeros((n,n))

qreigvals = qrmet(A)

for i, qre in enumerate(qreigvals):

eigvals[i], eigvecs[:,i] = invpowershift(A,qre+eps)

return eigvals, eigvecs

def testeigall(f,A):

eigvals, eigvecs = f(A)

npeigvals, npeigvecs = np.linalg.eig(A)

print(eigvals); print(npeigvals)

print(" ")

for eigvec, npeigvec in zip(eigvecs.T,npeigvecs.T):

print(eigvec); print(npeigvec)

print(" ")

if __name__ == '__main__':

A, bs = testcreate(4,21)

testeigall(eig,A)