Symmetric rank-2 update

F_SSYR2/F_DSYR2/F_CSYR2/F_ZSYR2

 

INTEGER*4

INCX, INCY, LDA, N, UPLO

 

COMPLEX*16

ALPHA, BETA

 

COMPLEX*16

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

 

SUBROUTINE F_ZSYR2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

VECLIB8

 

 

INTEGER*8

INCX, INCY, LDA, N, UPLO

 

REAL*4

ALPHA, BETA

 

REAL*4

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

 

SUBROUTINE F_SSYR2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

INTEGER*8

INCX, INCY, LDA, N, UPLO

 

REAL*8

ALPHA, BETA

 

REAL*8

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

 

SUBROUTINE F_DSYR2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

INTEGER*8

INCX, INCY, LDA, N, UPLO

 

COMPLEX*8

ALPHA, BETA

 

COMPLEX*8

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

 

SUBROUTINE F_CSYR2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

 

INTEGER*8

INCX, INCY, LDA, N, UPLO

 

COMPLEX*16

ALPHA, BETA

 

COMPLEX*16

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

 

SUBROUTINE F_ZSYR2 (UPLO, N, ALPHA, X, INCX, Y, INCY, BETA, A,

 

LDA)

 

Input

UPLO

Specifies whether a triangular matrix is upper or lower

 

 

triangular. Use either BLAS_UPPER or BLAS_LOWER.

 

N

Number of elements of vector x.

 

ALPHA

The scalar ALPHA.

 

X

REAL or COMPLEX array, minimum length

 

 

(N - 1) x incx + 1.

 

INCX

Increment for the array x. A vector x having component

 

 

xi, i = 1,..., n, is stored in an array X() with increment

 

 

argument incx. If incx > 0 then xi is stored in

 

 

X (1 + (i - 1) x incx). If incx < 0 then xi is stored in

 

 

X (1 + (N - i) x incx). incx = 0 is an illegal value.

Chapter 3 Basic Matrix Operations 395