F_CHER2/F_ZHER2

 

 

Hermitian rank-2 update

Name

F_CHER2/F_ZHER2

 

 

 

 

 

 

Hermitian rank-2 update

 

 

 

 

 

Purpose

F_xHER2 performs the Hermitian rank-2 update

 

A ← αx y∗ +

a

yx∗ + βA with A=A∗

 

where A is a complex Hermitian matrix, α is a complex scalar,

α

is the complex

 

conjugate of α, x and y are complex n-vectors, and x* and y* are the conjugate

 

transposes of x and y, respectively. β is a real scalar. The routine returns

 

immediately if n is less than or equal to zero.

 

Refer to “SSYR2/DSYR2/CHER2/ZHER2” on page 279 for a description of the

 

equivalent HP MLIB legacy BLAS subprograms.

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, INCY, LDA, N, UPLO

 

REAL*4

BETA

 

COMPLEX*8

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

 

SUBROUTINE F_CHER2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

 

 

 

 

INTEGER*4

INCX, INCY, LDA, N, UPLO

 

REAL*8

BETA

 

COMPLEX*16

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

 

SUBROUTINE F_ZHER2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

 

 

 

 

VECLIB8

 

 

 

 

 

 

INTEGER*8

INCX, INCY, LDA, N, UPLO

 

REAL*4

BETA

 

COMPLEX*8

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

 

SUBROUTINE F_CHER2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

 

 

 

346HP MLIB User’s Guide