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.