
ZHER(l) BLAS routine ZHER(l)
NAME
ZHER  perform the hermitian rank 1 operation A := alpha*x*conjg( x' ) + A,
SYNOPSIS
SUBROUTINE ZHER ( UPLO, N, ALPHA, X, INCX, A, LDA )
DOUBLE PRECISION ALPHA
INTEGER INCX, LDA, N
CHARACTER*1 UPLO
COMPLEX*16 A( LDA, * ), X( * )
PURPOSE
ZHER performs the hermitian rank 1 operation
where alpha is a real scalar, x is an n element vector and A is an n by n hermitian
matrix.
PARAMETERS
UPLO  CHARACTER*1.
On entry, UPLO specifies whether the upper or lower triangular part of the array A
is to be referenced as follows:
UPLO = 'U' or 'u' Only the upper triangular part of A is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of A is to be referenced.
Unchanged on exit.
N  INTEGER.
On entry, N specifies the order of the matrix A. N must be at least zero.
Unchanged on exit.
ALPHA  DOUBLE PRECISION.
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
X  COMPLEX*16 array of dimension at least
( 1 + ( n  1 )*abs( INCX ) ). Before entry, the incremented array X must contain
the n element vector x. Unchanged on exit.
INCX  INTEGER.
On entry, INCX specifies the increment for the elements of X. INCX must not be
zero. Unchanged on exit.
A  COMPLEX*16 array of DIMENSION ( LDA, n ).
Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of
the array A must contain the upper triangular part of the hermitian matrix and the
strictly lower triangular part of A is not referenced. On exit, the upper triangu
lar part of the array A is overwritten by the upper triangular part of the updated
matrix. Before entry with UPLO = 'L' or 'l', the leading n by n lower triangular
part of the array A must contain the lower triangular part of the hermitian matrix
and the strictly upper triangular part of A is not referenced. On exit, the lower
triangular part of the array A is overwritten by the lower triangular part of the
updated matrix. Note that the imaginary parts of the diagonal elements need not be
set, they are assumed to be zero, and on exit they are set to zero.
LDA  INTEGER.
On entry, LDA specifies the first dimension of A as declared in the calling (sub)
program. LDA must be at least max( 1, n ). Unchanged on exit.
Level 2 Blas routine.
 Written on 22October1986. Jack Dongarra, Argonne National Lab. Jeremy Du
Croz, Nag Central Office. Sven Hammarling, Nag Central Office. Richard Hanson,
Sandia National Labs.
BLAS routine 16 October 1992 ZHER(l) 
