cspmv.f(3)

NAME
cspmv.f -

SYNOPSIS

  Functions/Subroutines

subroutine cspmv (UPLO, N, ALPHA, AP, X, INCX, BETA, Y, INCY)
CSPMV computes a matrix-vector product for complex vectors using a complex symmetric packed matrix

Function/Subroutine Documentation

  subroutine cspmv (characterUPLO, integerN, complexALPHA, complex, dimension( * )AP, complex, dimension( * )X, integerINCX, complexBETA, complex, dimension( * )Y, integerINCY)

CSPMV computes a matrix-vector product for complex vectors using a complex symmetric packed matrix

Purpose:

     CSPMV  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.

Parameters:
    UPLO

              UPLO is 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

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

    ALPHA

              ALPHA is COMPLEX
               On entry, ALPHA specifies the scalar alpha.
               Unchanged on exit.

    AP

              AP is COMPLEX 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

              X is COMPLEX 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

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

    BETA

              BETA is COMPLEX
               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

              Y is COMPLEX 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

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

Author:
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Date:
    September 2012

Definition at line 152 of file cspmv.f.

Author

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