NAME¶
PZPTTRS - solve a system of linear equations A(1:N, JA:JA+N-1) * X =
B(IB:IB+N-1, 1:NRHS)
SYNOPSIS¶
- SUBROUTINE PZPTTRS(
- 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*16
- AF( * ), B( * ), E( * ), WORK( * )
- DOUBLE
- PRECISION D( * )
PURPOSE¶
PZPTTRS 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 PZPTTRF.
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 PZPTTRF.
Routine PZPTTRF MUST be called first.