DragonFly On-Line Manual Pages

chpr2.f(3)                          LAPACK                          chpr2.f(3)

NAME
       chpr2.f -

SYNOPSIS
   Functions/Subroutines
       subroutine chpr2 (UPLO, N, ALPHA, X, INCX, Y, INCY, AP)
           CHPR2

Function/Subroutine Documentation
   subroutine chpr2 (characterUPLO, integerN, complexALPHA, complex,
       dimension(*)X, integerINCX, complex, dimension(*)Y, integerINCY,
       complex, dimension(*)AP)
       CHPR2 Purpose:

            CHPR2  performs the hermitian rank 2 operation

               A := alpha*x*y**H + conjg( alpha )*y*x**H + A,

            where alpha is a scalar, x and y are n element vectors and A is an
            n by n hermitian 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 COMPLEX
                      On entry, ALPHA specifies the scalar alpha.

           X

                     X is COMPLEX 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.

           Y

                     Y is COMPLEX array of 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 COMPLEX 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 hermitian 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 hermitian 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.
                      Note that the imaginary parts of the diagonal elements need
                      not be set, they are assumed to be zero, and on exit they
                      are set to zero.

       Author:
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Date:
           November 2011

       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 146 of file chpr2.f.

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

Version 3.4.2                   Sat Nov 16 2013                     chpr2.f(3)