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zpttrf.3lapack
Langue: en
Version: 290885 (debian - 07/07/09)
Section: 3 (Bibliothèques de fonctions)
NAME
ZPTTRF - computes the L*D*L' factorization of a complex Hermitian positive definite tridiagonal matrix ASYNOPSIS
- SUBROUTINE ZPTTRF(
- N, D, E, INFO )
- INTEGER INFO, N
- DOUBLE PRECISION D( * )
- COMPLEX*16 E( * )
PURPOSE
ZPTTRF computes the L*D*L' factorization of a complex Hermitian positive definite tridiagonal matrix A. The factorization may also be regarded as having the form A = U'*D*U.ARGUMENTS
- N (input) INTEGER
- The order of the matrix A. N >= 0.
- D (input/output) DOUBLE PRECISION array, dimension (N)
- On entry, the n diagonal elements of the tridiagonal matrix A. On exit, the n diagonal elements of the diagonal matrix D from the L*D*L' factorization of A.
- E (input/output) COMPLEX*16 array, dimension (N-1)
- On entry, the (n-1) subdiagonal elements of the tridiagonal matrix A. On exit, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L' factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the U'*D*U factorization of A.
- INFO (output) INTEGER
- = 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
> 0: if INFO = k, the leading minor of order k is not positive definite; if k < N, the factorization could not be completed, while if k = N, the factorization was completed, but D(N) <= 0.
Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre