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pythonsortingeigenvector

Sorting eigen values and corresponding eigen vectors

For a matrix A, I have a set of eigenvalues and corresponding eigenvectors, obtained using the standard method, eigvals, eigvecs = la.eig(A) after importing scipy.linalg as la.
The eigenvalues are sorted using np.sort(eigvals, axis=-0).
How do we rearrange the corresponding eigenvectors.

Solution

  • I believe what you need is to get the list of sorted indexes, then take eigenvectors and eigenvalues in that order using np.argsort.

    It would be something like:

    import numpy as np
import scipy.linalg as la

A =  np.random.rand(3, 3)
eigvals, eigvecs = la.eig(A)
sorted_indexes = np.argsort(eigvals)
eigvals = eigvals[sorted_indexes]
eigvecs = eigvecs[:,sorted_indexes]

    P.S.: seems @srikrishna already posted a link with the solution. I will maintain the response stays in Stackoverflow.