naginterfaces.library.lapacklin.zgetri¶

naginterfaces.library.lapacklin.zgetri(a, ipiv)[source]

zgetri computes the inverse of a complex matrix , where has been factorized by zgetrf().

For full information please refer to the NAG Library document for f07aw

https://www.nag.com/numeric/nl/nagdoc_27.3/flhtml/f07/f07awf.html

Parameters
acomplex, array-like, shape

The factorization of , as returned by zgetrf().

ipivint, array-like, shape

The pivot indices, as returned by zgetrf().

Returns
acomplex, ndarray, shape

The factorization is overwritten by the matrix .

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: .

Warns
NagAlgorithmicWarning
(errno )

Element of the diagonal is zero. is singular, and the inverse of cannot be computed.

Notes

zgetri is used to compute the inverse of a complex matrix , the function must be preceded by a call to zgetrf(), which computes the factorization of as . The inverse of is computed by forming and then solving the equation for .

References

Du Croz, J J and Higham, N J, 1992, Stability of methods for matrix inversion, IMA J. Numer. Anal. (12), 1–19