Hermitian rank-1 update

 

F_CHPR/F_ZHPR

 

N

Number of elements of vector x.

 

ALPHA

REAL 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

REAL scalar BETA.

 

AP

Complex array, dimension (LDA, N). Contains the

 

 

upper or lower triangle, as specified by uplo of an

 

 

n-by-nreal symmetric or complex Hermitian matrix A,

 

 

stored by columns in packed form.

Output

AP

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

 

 

specified by uplo, replaces the input.

 

 

A ← αxx+ β Awith A=A

Chapter 3 Basic Matrix Operations 351