dsymv.f

dsymv.f(3)                          LAPACK                          dsymv.f(3)



NAME
       dsymv.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dsymv (UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
           DSYMV

Function/Subroutine Documentation
   subroutine dsymv (characterUPLO, integerN, double precisionALPHA, double
       precision, dimension(lda,*)A, integerLDA, double precision,
       dimension(*)X, integerINCX, double precisionBETA, double precision,
       dimension(*)Y, integerINCY)
       DSYMV Purpose:


            DSYMV  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.

       Parameters:
           UPLO

                     UPLO is 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.

           N

                     N is INTEGER
                      On entry, N specifies the order of the matrix A.
                      N must be at least zero.

           ALPHA

                     ALPHA is DOUBLE PRECISION.
                      On entry, ALPHA specifies the scalar alpha.

           A

                     A is DOUBLE PRECISION array of 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.

           LDA

                     LDA is 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 ).

           X

                     X is 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.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.

           BETA

                     BETA is DOUBLE PRECISION.
                      On entry, BETA specifies the scalar beta. When BETA is
                      supplied as zero then Y need not be set on input.

           Y

                     Y is 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

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.

       Author:
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Date:
           November 2011

       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.

       Definition at line 153 of file dsymv.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.



Version 3.4.2                   Tue Sep 25 2012                     dsymv.f(3)