man pcdbtrsv (Fonctions bibliothèques) - solve a banded triangular system of linear equations A(1:N, JA:JA+N-1) * X = B(IB:IB+N-1, 1:NRHS)

NAME

PCDBTRSV - solve a banded triangular system of linear equations A(1:N, JA:JA+N-1) * X = B(IB:IB+N-1, 1:NRHS)

SYNOPSIS

SUBROUTINE PCDBTRSV(
UPLO, TRANS, N, BWL, BWU, NRHS, A, JA, DESCA, B, IB, DESCB, AF, LAF, WORK, LWORK, INFO )
CHARACTER TRANS, UPLO
INTEGER BWL, BWU, IB, INFO, JA, LAF, LWORK, N, NRHS
INTEGER DESCA( * ), DESCB( * )
COMPLEX A( * ), AF( * ), B( * ), WORK( * )

PURPOSE

PCDBTRSV solves a banded triangular system of linear equations or

A(1:N, JA:JA+N-1)^H * X = B(IB:IB+N-1, 1:NRHS)

where A(1:N, JA:JA+N-1) is a banded

triangular matrix factor produced by the

Gaussian elimination code PC@(dom_pre)BTRF

and is stored in A(1:N,JA:JA+N-1) and AF.

The matrix stored in A(1:N, JA:JA+N-1) is either

upper or lower triangular according to UPLO,

and the choice of solving A(1:N, JA:JA+N-1) or A(1:N, JA:JA+N-1)^H is dictated by the user by the parameter TRANS.

Routine PCDBTRF MUST be called first.