Triangular solve

 

F_STRSV/F_DTRSV/F_CTRSV/F_ZTRSV

Name

F_STRSV/F_DTRSV/F_CTRSV/F_ZTRSV

 

Triangular solve

 

Purpose

F_xTRSV solves one of the following equations:

 

x ← αT–1x

 

x ← αT–Tx

 

x ← αT–*x

 

where x is a vector and the matrix T is a unit, non-unit, upper, or lower

 

triangular matrix. T−T is the inverse of the transpose of T, and T–*is the

 

inverse of the conjugate transpose of T.

 

Refer to “STRSV/DTRSV/CTRSV/ZTRSV” on page 332 for a description of the

 

equivalent HP MLIB legacy BLAS subprograms.

Matrix

For these subprograms, you supply A in a two-dimensional array large enough

Storage

to hold a square matrix. The other triangle of the array is not referenced. If A

 

has an unstored unit diagonal (see input argument DIAG), then the diagonal

 

elements of the array also are not referenced.

Usage

VECLIB

 

 

INTEGER*4

DIAG, INCX, N, TRANS, UPLO

 

REAL*4

ALPHA, A( LDA, * ), X( * )

 

SUBROUTINE F_STRSV (UPLO, TRANS, DIAG, N, ALPHA, A, LDA, X,

 

INCX)

 

 

INTEGER*4

DIAG, INCX, N, TRANS, UPLO

 

REAL*8

ALPHA, A( LDA, * ), X( * )

 

SUBROUTINE F_DTRSV (UPLO, TRANS, DIAG, N, ALPHA, A, LDA, X,

 

INCX)

 

 

INTEGER*4

DIAG, INCX, N, TRANS, UPLO

 

COMPLEX*8

ALPHA, A( LDA, * ), X( * )

 

SUBROUTINE F_CTRSV (UPLO, TRANS, DIAG, N, ALPHA, A, LDA, X,

 

INCX)

 

 

INTEGER*4

DIAG, INCX, N, TRANS, UPLO

 

COMPLEX*16

ALPHA, A( LDA, * ), X( * )

 

SUBROUTINE F_ZTRSV (UPLO, TRANS, DIAG, N, ALPHA, A, LDA, X,

 

INCX)

 

VECLIB8

Chapter 3 Basic Matrix Operations 417