TESTING/EIG/chst01.f(3)    Library Functions Manual    TESTING/EIG/chst01.f(3)

NAME
       TESTING/EIG/chst01.f

SYNOPSIS
   Functions/Subroutines
       subroutine chst01 (n, ilo, ihi, a, lda, h, ldh, q, ldq, work, lwork,
           rwork, result)
           CHST01

Function/Subroutine Documentation
   subroutine chst01 (integer n, integer ilo, integer ihi, complex, dimension(
       lda, * ) a, integer lda, complex, dimension( ldh, * ) h, integer ldh,
       complex, dimension( ldq, * ) q, integer ldq, complex, dimension( lwork
       ) work, integer lwork, real, dimension( * ) rwork, real, dimension( 2 )
       result)
       CHST01

       Purpose:


            CHST01 tests the reduction of a general matrix A to upper Hessenberg
            form:  A = Q*H*Q'.  Two test ratios are computed;

            RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )
            RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )

            The matrix Q is assumed to be given explicitly as it would be
            following CGEHRD + CUNGHR.

            In this version, ILO and IHI are not used, but they could be used
            to save some work if this is desired.

       Parameters
           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER

                     A is assumed to be upper triangular in rows and columns
                     1:ILO-1 and IHI+1:N, so Q differs from the identity only in
                     rows and columns ILO+1:IHI.

           A

                     A is COMPLEX array, dimension (LDA,N)
                     The original n by n matrix A.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,N).

           H

                     H is COMPLEX array, dimension (LDH,N)
                     The upper Hessenberg matrix H from the reduction A = Q*H*Q'
                     as computed by CGEHRD.  H is assumed to be zero below the
                     first subdiagonal.

           LDH

                     LDH is INTEGER
                     The leading dimension of the array H.  LDH >= max(1,N).

           Q

                     Q is COMPLEX array, dimension (LDQ,N)
                     The orthogonal matrix Q from the reduction A = Q*H*Q' as
                     computed by CGEHRD + CUNGHR.

           LDQ

                     LDQ is INTEGER
                     The leading dimension of the array Q.  LDQ >= max(1,N).

           WORK

                     WORK is COMPLEX array, dimension (LWORK)

           LWORK

                     LWORK is INTEGER
                     The length of the array WORK.  LWORK >= 2*N*N.

           RWORK

                     RWORK is REAL array, dimension (N)

           RESULT

                     RESULT is REAL array, dimension (2)
                     RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )
                     RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 138 of file chst01.f.

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

LAPACK                          Version 3.12.0         TESTING/EIG/chst01.f(3)