NAME¶

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

SYNOPSIS¶

SUBROUTINE PSPTTRSV(

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( * ) REAL AF( * ), B( * ), D( * ), E( * ), WORK( * )

PURPOSE¶

PSPTTRSV solves a tridiagonal triangular system of linear equations
or
A(1:N, JA:JA+N-1)^T * X = B(IB:IB+N-1, 1:NRHS) where A(1:N, JA:JA+N-1) is a tridiagonal triangular matrix factor produced by the Cholesky factorization code PSPTTRF 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)^T is dictated by the user by the parameter TRANS. Routine PSPTTRF MUST be called first.