signm — SciPy v1.15.3 Manual (original) (raw)

scipy.linalg.

scipy.linalg.signm(A, disp=True)[source]#

Matrix sign function.

Extension of the scalar sign(x) to matrices.

Parameters:

A(N, N) array_like

Matrix at which to evaluate the sign function

dispbool, optional

Print warning if error in the result is estimated large instead of returning estimated error. (Default: True)

Returns:

signm(N, N) ndarray

Value of the sign function at A

errestfloat

(if disp == False)

1-norm of the estimated error, ||err||_1 / ||A||_1

Examples

from scipy.linalg import signm, eigvals a = [[1,2,3], [1,2,1], [1,1,1]] eigvals(a) array([ 4.12488542+0.j, -0.76155718+0.j, 0.63667176+0.j]) eigvals(signm(a)) array([-1.+0.j, 1.+0.j, 1.+0.j])