sspmv(3) [debian man page]

SSPMV(3)							   BLAS routine 							  SSPMV(3)

NAME

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

SYNOPSIS

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

	   REAL 	ALPHA, BETA

	   INTEGER	INCX, INCY, N

	   CHARACTER*1	UPLO

	   REAL 	AP( * ), X( * ), Y( * )

PURPOSE

       SSPMV  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 symmetric 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  - REAL		.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       AP     - REAL		 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 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 symmet-
	      ric 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      - REAL		 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   - REAL		.
	      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      - REAL		 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 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
	      tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							  SSPMV(3)

DSPMV(l)							   BLAS routine 							  DSPMV(l)

NAME

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

SYNOPSIS

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

	   DOUBLE	PRECISION ALPHA, BETA

	   INTEGER	INCX, INCY, N

	   CHARACTER*1	UPLO

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

PURPOSE

       DSPMV  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 symmetric 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  - DOUBLE PRECISION.
	      On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.

       AP     - DOUBLE PRECISION 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 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 symmet-
	      ric 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      - DOUBLE PRECISION 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   - DOUBLE PRECISION.
	      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      - DOUBLE PRECISION 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 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
	      tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							  DSPMV(l)