TESTING/LIN/dqrt03.f(3)    Library Functions Manual    TESTING/LIN/dqrt03.f(3)

NAME
       TESTING/LIN/dqrt03.f

SYNOPSIS
   Functions/Subroutines
       subroutine dqrt03 (m, n, k, af, c, cc, q, lda, tau, work, lwork, rwork,
           result)
           DQRT03

Function/Subroutine Documentation
   subroutine dqrt03 (integer m, integer n, integer k, double precision,
       dimension( lda, * ) af, double precision, dimension( lda, * ) c, double
       precision, dimension( lda, * ) cc, double precision, dimension( lda, *
       ) q, integer lda, double precision, dimension( * ) tau, double
       precision, dimension( lwork ) work, integer lwork, double precision,
       dimension( * ) rwork, double precision, dimension( * ) result)
       DQRT03

       Purpose:


            DQRT03 tests DORMQR, which computes Q*C, Q'*C, C*Q or C*Q'.

            DQRT03 compares the results of a call to DORMQR with the results of
            forming Q explicitly by a call to DORGQR and then performing matrix
            multiplication by a call to DGEMM.

       Parameters
           M

                     M is INTEGER
                     The order of the orthogonal matrix Q.  M >= 0.

           N

                     N is INTEGER
                     The number of rows or columns of the matrix C; C is m-by-n if
                     Q is applied from the left, or n-by-m if Q is applied from
                     the right.  N >= 0.

           K

                     K is INTEGER
                     The number of elementary reflectors whose product defines the
                     orthogonal matrix Q.  M >= K >= 0.

           AF

                     AF is DOUBLE PRECISION array, dimension (LDA,N)
                     Details of the QR factorization of an m-by-n matrix, as
                     returned by DGEQRF. See DGEQRF for further details.

           C

                     C is DOUBLE PRECISION array, dimension (LDA,N)

           CC

                     CC is DOUBLE PRECISION array, dimension (LDA,N)

           Q

                     Q is DOUBLE PRECISION array, dimension (LDA,M)

           LDA

                     LDA is INTEGER
                     The leading dimension of the arrays AF, C, CC, and Q.

           TAU

                     TAU is DOUBLE PRECISION array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors corresponding
                     to the QR factorization in AF.

           WORK

                     WORK is DOUBLE PRECISION array, dimension (LWORK)

           LWORK

                     LWORK is INTEGER
                     The length of WORK.  LWORK must be at least M, and should be
                     M*NB, where NB is the blocksize for this environment.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (M)

           RESULT

                     RESULT is DOUBLE PRECISION array, dimension (4)
                     The test ratios compare two techniques for multiplying a
                     random matrix C by an m-by-m orthogonal matrix Q.
                     RESULT(1) = norm( Q*C - Q*C )  / ( M * norm(C) * EPS )
                     RESULT(2) = norm( C*Q - C*Q )  / ( M * norm(C) * EPS )
                     RESULT(3) = norm( Q'*C - Q'*C )/ ( M * norm(C) * EPS )
                     RESULT(4) = norm( C*Q' - C*Q' )/ ( M * norm(C) * EPS )

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 134 of file dqrt03.f.

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

LAPACK                          Version 3.12.0         TESTING/LIN/dqrt03.f(3)