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

- SUBROUTINE PSDTTRSV(
- UPLO, TRANS, N, NRHS, DL, D, DU, JA, DESCA, B, IB, DESCB, AF, LAF, WORK,
LWORK, INFO )

CHARACTER TRANS, UPLO INTEGER IB, INFO, JA, LAF, LWORK, N, NRHS INTEGER DESCA( *
), DESCB( * ) REAL AF( * ), B( * ), D( * ), DL( * ), DU( * ), WORK( * )

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

Gaussian elimination code PS@(dom_pre)TTRF

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 PSDTTRF MUST be called first.