Residual Norm of Eigenpair

Problem

Measure how well the pair (lam, v) satisfies the eigenvalue equation for A:

residual = ||A*v - lam*v||_2

A residual near 0 indicates an accurate eigenpair.

Hint

This is the norm of the residual vector for a single eigenpair.

case 1

in: [[[2,0],[0,3]],2,[1,0]]

expected: 0

case 2

in: [[[2,0],[0,3]],2,[1,1]]

expected: 1

case 3

in: [[[0,1],[1,0]],1,[1,1]]

expected: 0

case 4

in: [[[4,1],[2,3]],2,[1,0]]

expected: 2.8284271247461903

Starter codePython

def eigenpair_residual(A, lam, v):
    # Your code here
    pass

4 test cases · run your code against them in the editor