CXML
        	    
LAPACK version 3.0
zspmv(3)

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

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

      CHARACTER	    UPLO

      INTEGER	    INCX, INCY, N

      COMPLEX*16    ALPHA, BETA

      COMPLEX*16    AP( * ), X( * ), Y( * )

DESCRIPTION
  ZSPMV 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, 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, 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 symmetric
	 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 symmetric
	 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.  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.