redhat man page for zsymv

ZSYMV(l)								 )								  ZSYMV(l)

NAME
       ZSYMV - perform the matrix-vector operation  y := alpha*A*x + beta*y,

SYNOPSIS
       SUBROUTINE ZSYMV( UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )

	   CHARACTER	 UPLO

	   INTEGER	 INCX, INCY, LDA, N

	   COMPLEX*16	 ALPHA, BETA

	   COMPLEX*16	 A( LDA, * ), X( * ), Y( * )

PURPOSE
       ZSYMV  performs	the matrix-vector operation y := alpha*A*x + beta*y, where alpha and beta are scalars, x and y are n element vectors and A
       is an n by n symmetric matrix.

ARGUMENTS
       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  - COMPLEX*16
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       A      - COMPLEX*16 array, 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 symmetric matrix and the strictly lower triangular part of A is not referenced.  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  symmetric  matrix  and  the
	      strictly upper triangular part of A is not referenced.  Unchanged on exit.

       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.

       X      - COMPLEX*16 array, 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, 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.

LAPACK version 3.0						   15 June 2000 							  ZSYMV(l)