F_CHER/F_ZHER

Hermitian rank-1 update

Name

F_CHER/F_ZHER

 

 

Hermitian rank-1 update

Purpose

F_xHER performs the Hermitian rank-1 update

 

A ← αxx∗ + β A∗ with

A=A∗

 

where A is an n-by-ncomplex Hermitian matrix, α is a real scalar, x is a

 

complex n-vector, and x* is the conjugate transpose of x. The routine returns

 

immediately if n is less than or equal to zero.

 

Refer to “SSYR/DSYR/CHER/ZHER” on page 275 for a description of the HP

 

MLIB legacy BLAS subprogram for rank-1 update.

Matrix

Because either triangle of A can be obtained from the other, these subprograms

Storage

reference and apply the update to only one triangle of A. You can supply either

 

the upper or the lower triangle of A, in a two-dimensional array large enough to

 

hold the entire matrix, and the same triangle of the updated matrix is returned

 

in the array. The other triangle of the array is not referenced.

Usage

VECLIB

 

 

INTEGER*4

INCX, LDA, N, UPLO

 

REAL*4

ALPHA, BETA

 

COMPLEX*8

A( LDA, * ), X( * )

 

SUBROUTINE F_CHER (UPLO, N, ALPHA, X, INCX, BETA, A, LDA)

 

INTEGER*4

INCX, LDA, N, UPLO

 

REAL*8

ALPHA, BETA

 

COMPLEX*16

A( LDA, * ), X( * )

 

SUBROUTINE F_ZHER (UPLO, N, ALPHA, X, INCX, BETA, A, LDA)

 

VECLIB8

 

 

INTEGER*8

INCX, LDA, N, UPLO

 

REAL*4

ALPHA, BETA

 

COMPLEX*8

A( LDA, * ), X( * )

 

SUBROUTINE F_CHER (UPLO, N, ALPHA, X, INCX, BETA, A, LDA)

 

INTEGER*8

INCX, LDA, N, UPLO

 

REAL*8

ALPHA, BETA

 

COMPLEX*16

A( LDA, * ), X( * )

 

SUBROUTINE F_ZHER (UPLO, N, ALPHA, X, INCX, BETA, A, LDA)

Input

UPLO

Specifies whether a triangular matrix is upper or lower

 

 

triangular. Use either BLAS_UPPER or BLAS_LOWER.

344HP MLIB User’s Guide