NAME
PCPTTRSV - 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 PCPTTRSV(
-
UPLO, TRANS, N, NRHS, D, E, JA, DESCA, B, IB, DESCB, AF, LAF, WORK, LWORK, INFO )
- CHARACTER
-
TRANS, UPLO
- INTEGER
-
IB, INFO, JA, LAF, LWORK, N, NRHS
- INTEGER
-
DESCA( * ), DESCB( * )
- COMPLEX
-
AF( * ), B( * ), E( * ), WORK( * )
- REAL
-
D( * )
PURPOSE
PCPTTRSV solves a tridiagonal 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 tridiagonal
triangular matrix factor produced by the
Cholesky factorization code PCPTTRF
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 PCPTTRF MUST be called first.