F_SSYR2/F_DSYR2/F_CSYR2/F_ZSYR2

Symmetric rank-2 update

 

Y

REAL or COMPLEX array, minimum length

 

 

 

 

(N - 1) x incy + 1.

 

INCY

Increment for the array y. A vector y having component

 

 

 

 

yi, i = 1,..., n, is stored in an array Y() with increment

 

 

 

 

argument incy. If incy > 0 then yi is stored in

 

 

 

 

Y(1 + (i - 1) x incy). If incy < 0 then yi is stored in

 

 

 

 

Y(1 + (N - i) x incy). incy = 0 is an illegal value.

 

BETA

The scalar BETA.

 

A

REAL or COMPLEX array, dimension (LDA, N).

 

LDA

Leading dimension of array A. If lda < 1 or lda < n, an

 

 

 

 

error condition is generated.

Output

A

The upper or lower triangle of the updated A matrix, as

 

 

 

 

specified by uplo, replaces the upper or lower triangle

 

 

 

 

of the input, respectively. The other triangle of A is

 

 

 

 

unchanged.

 

A ← αx yT +

α

yxT + βA

with A=AT

396HP MLIB User’s Guide