sort eigenvalues and associated eigenvectors after using numpy.linalg.eig in python

by

Use numpy.argsort. It returns the indices one would use to sort the array.

import numpy as np
import numpy.linalg as linalg

A = np.random.random((3,3))
eigenValues, eigenVectors = linalg.eig(A)

idx = eigenValues.argsort()[::-1]   
eigenValues = eigenValues[idx]
eigenVectors = eigenVectors[:,idx]

If the eigenvalues are complex, the sort order is lexicographic (that is, complex numbers are sorted according to their real part first, with ties broken by their imaginary part).

More Related Contents:

  1. Sorting arrays in NumPy by column
  2. Rank items in an array using Python/NumPy, without sorting array twice
  3. A fast way to find the largest N elements in an numpy array
  4. Sorting a 2D numpy array by multiple axes
  5. How can I “zip sort” parallel numpy arrays?
  6. Find elements of array one nearest to elements of array two
  7. Sort invariant for numpy.argsort with multiple dimensions
  8. Efficiently sorting a numpy array in descending order?
  9. Sorting a python array/recarray by column
  10. argsort for a multidimensional ndarray
  11. Sort array’s rows by another array in Python
  12. Convert array dictionary to a dictionary python
  13. How do I get indices of N maximum values in a NumPy array?
  14. Fast Haversine Approximation (Python/Pandas)
  15. Index n dimensional array with (n-1) d array
  16. how does multiplication differ for NumPy Matrix vs Array classes?
  17. How to sort objects by multiple keys?
  18. How to increase Jupyter notebook Memory limit?
  19. How to split/partition a dataset into training and test datasets for, e.g., cross validation?
  20. Installing NumPy and SciPy on 64-bit Windows (with Pip)
  21. Overflow Error in Python’s numpy.exp function
  22. Numpy element-wise dot product
  23. Creating same random number sequence in Python, NumPy and R
  24. NumPy, RuntimeWarning: invalid value encountered in power
  25. Function to determine if two numbers are nearly equal when rounded to n significant decimal digits
  26. Why is B = numpy.dot(A,x) so much slower looping through doing B[i,:,:] = numpy.dot(A[i,:,:],x) )?
  27. numpy division with RuntimeWarning: invalid value encountered in double_scalars
  28. Is the order of a Python dictionary guaranteed over iterations?
  29. Vectorizing `numpy.random.choice` for given 2D array of probabilities along an axis
  30. How can I turn a flat list into a 2D array in python?

Leave a Comment