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

NAME

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

SYNOPSIS

SUBROUTINE PCPTTRS(
UPLO, N, NRHS, D, E, JA, DESCA, B, IB, DESCB, AF, LAF, WORK, LWORK, INFO )
CHARACTER UPLO
INTEGER IB, INFO, JA, LAF, LWORK, N, NRHS
INTEGER DESCA( * ), DESCB( * )
COMPLEX AF( * ), B( * ), E( * ), WORK( * )
REAL D( * )

PURPOSE

PCPTTRS solves a system of linear equations

where A(1:N, JA:JA+N-1) is the matrix used to produce the factors stored in A(1:N,JA:JA+N-1) and AF by PCPTTRF.

A(1:N, JA:JA+N-1) is an N-by-N complex

tridiagonal symmetric positive definite distributed

matrix.

Depending on the value of UPLO, A stores either U or L in the equn A(1:N, JA:JA+N-1) = U'D *U or L*D L' as computed by PCPTTRF.

Routine PCPTTRF MUST be called first.