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pzpbtrf
Langue: en
Version: 283543 (debian - 07/07/09)
Section: 3 (Bibliothèques de fonctions)
NAME
PZPBTRF - compute a Cholesky factorization of an N-by-N complex banded symmetric positive definite distributed matrix with bandwidth BWSYNOPSIS
- SUBROUTINE PZPBTRF(
- UPLO, N, BW, A, JA, DESCA, AF, LAF, WORK, LWORK, INFO )
- CHARACTER UPLO
- INTEGER BW, INFO, JA, LAF, LWORK, N
- INTEGER DESCA( * )
- COMPLEX*16 A( * ), AF( * ), WORK( * )
PURPOSE
PZPBTRF computes a Cholesky factorization of an N-by-N complex banded symmetric positive definite distributed matrix with bandwidth BW: A(1:N, JA:JA+N-1). Reordering is used to increase parallelism in the factorization. This reordering results in factors that are DIFFERENT from those produced by equivalent sequential codes. These factors cannot be used directly by users; however, they can be used insubsequent calls to PZPBTRS to solve linear systems.
The factorization has the form
P A(1:N, JA:JA+N-1) P^T = U' U , if UPLO = 'U', or
P A(1:N, JA:JA+N-1) P^T = L L', if UPLO = 'L'
where U is a banded upper triangular matrix and L is banded lower triangular, and P is a permutation matrix.
Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre