
ZHPMV(l) BLAS routine ZHPMV(l)
NAME
ZHPMV  perform the matrixvector operation y := alpha*A*x + beta*y,
SYNOPSIS
SUBROUTINE ZHPMV ( UPLO, N, ALPHA, AP, X, INCX, BETA, Y, INCY )
COMPLEX*16 ALPHA, BETA
INTEGER INCX, INCY, N
CHARACTER*1 UPLO
COMPLEX*16 AP( * ), X( * ), Y( * )
PURPOSE
ZHPMV performs the matrixvector operation
where alpha and beta are scalars, x and y are n element vectors and A is an n by n hermit
ian matrix, supplied in packed form.
PARAMETERS
UPLO  CHARACTER*1.
On entry, UPLO specifies whether the upper or lower triangular part of the matrix A
is supplied in the packed array AP as follows:
UPLO = 'U' or 'u' The upper triangular part of A is supplied in AP.
UPLO = 'L' or 'l' The lower triangular part of A is supplied in AP.
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  COMPLEX*16 .
On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
AP  COMPLEX*16 array of DIMENSION at least
( ( n*( n + 1 ) )/2 ). Before entry with UPLO = 'U' or 'u', the array AP must con
tain the upper triangular part of the hermitian matrix packed sequentially, column
by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2
) and a( 2, 2 ) respectively, and so on. Before entry with UPLO = 'L' or 'l', the
array AP must contain the lower triangular part of the hermitian matrix packed
sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP(
3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on. Note that the imagi
nary parts of the diagonal elements need not be set and are assumed to be zero.
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.
BETA  COMPLEX*16 .
On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need
not be set on input. Unchanged on exit.
Y  COMPLEX*16 array of dimension at least
( 1 + ( n  1 )*abs( INCY ) ). Before entry, the incremented array Y must contain
the n element vector y. On exit, Y is overwritten by the updated vector y.
INCY  INTEGER.
On entry, INCY specifies the increment for the elements of Y. INCY must not be
zero. 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 ZHPMV(l) 
