ZHPMV(1)

NAME
LAPACK-3 - performs the matrix-vector operation y := alpha*A*x + beta*y,

SYNOPSIS

SUBROUTINE ZHPMV(UPLO,N,ALPHA,AP,X,INCX,BETA,Y,INCY)

DOUBLE
    COMPLEX ALPHA,BETA

INTEGER
    INCX,INCY,N

CHARACTER
    UPLO

DOUBLE
    COMPLEX AP(*),X(*),Y(*)

PURPOSE
ZHPMV performs the matrix-vector operation
 where alpha and beta are scalars, x and y are n element vectors and
 A is an n by n hermitian matrix, supplied in packed form.

ARGUMENTS

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
     contain 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 imaginary 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.

FURTHER DETAILS
 Level 2 Blas routine.
 The vector and matrix arguments are not referenced when N = 0, or M = 0
 -- Written on 22-October-1986.
    Jack Dongarra, Argonne National Lab.
    Jeremy Du Croz, Nag Central Office.
    Sven Hammarling, Nag Central Office.
    Richard Hanson, Sandia National Labs.