Hermitian rank-1 update

 

F_CHER/F_ZHER

 

N

Number of elements of vector x.

 

ALPHA

The scalar ALPHA.

 

X

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.

 

BETA

The scalar BETA.

 

A

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 ← αxx∗ + β A∗ with A=A∗

Chapter 3 Basic Matrix Operations 345