BLAS/SRC/dspr2.f(3)        Library Functions Manual        BLAS/SRC/dspr2.f(3)

NAME
       BLAS/SRC/dspr2.f

SYNOPSIS
   Functions/Subroutines
       subroutine dspr2 (uplo, n, alpha, x, incx, y, incy, ap)
           DSPR2

Function/Subroutine Documentation
   subroutine dspr2 (character uplo, integer n, double precision alpha, double
       precision, dimension(*) x, integer incx, double precision, dimension(*)
       y, integer incy, double precision, dimension(*) ap)
       DSPR2

       Purpose:


            DSPR2  performs the symmetric rank 2 operation

               A := alpha*x*y**T + alpha*y*x**T + A,

            where alpha is a scalar, 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.

           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.

           X

                     X is DOUBLE PRECISION array, 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.

           Y

                     Y is DOUBLE PRECISION array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCY ) ).
                      Before entry, the incremented array Y must contain the n
                      element vector y.

           INCY

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

           AP

                     AP is DOUBLE PRECISION 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. On exit, the array
                      AP is overwritten by the upper triangular part of the
                      updated matrix.
                      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. On exit, the array
                      AP is overwritten by the lower triangular part of the
                      updated matrix.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:


             Level 2 Blas routine.

             -- 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 141 of file dspr2.f.

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

LAPACK                          Version 3.12.0             BLAS/SRC/dspr2.f(3)