TESTING/LIN/dqrt01.f(3)

NAME
TESTING/LIN/dqrt01.f

SYNOPSIS

  Functions/Subroutines
subroutine dqrt01 (m, n, a, af, q, r, lda, tau, work, lwork, rwork, result)
DQRT01

Function/Subroutine Documentation

  subroutine dqrt01 (integer m, integer n, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) q, double precision, dimension( lda, * ) r, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( * ) result)

DQRT01

Purpose:

    !>
    !> DQRT01 tests DGEQRF, which computes the QR factorization of an m-by-n
    !> matrix A, and partially tests DORGQR which forms the m-by-m
    !> orthogonal matrix Q.
    !>
    !> DQRT01 compares R with Q'*A, and checks that Q is orthogonal.
    !>

Parameters
    M

    !>          M is INTEGER
    !>          The number of rows of the matrix A.  M >= 0.
    !>

    N

    !>          N is INTEGER
    !>          The number of columns of the matrix A.  N >= 0.
    !>

    A

    !>          A is DOUBLE PRECISION array, dimension (LDA,N)
    !>          The m-by-n matrix A.
    !>

    AF

    !>          AF is DOUBLE PRECISION array, dimension (LDA,N)
    !>          Details of the QR factorization of A, as returned by DGEQRF.
    !>          See DGEQRF for further details.
    !>

    Q

    !>          Q is DOUBLE PRECISION array, dimension (LDA,M)
    !>          The m-by-m orthogonal matrix Q.
    !>

    R

    !>          R is DOUBLE PRECISION array, dimension (LDA,max(M,N))
    !>

    LDA

    !>          LDA is INTEGER
    !>          The leading dimension of the arrays A, AF, Q and R.
    !>          LDA >= max(M,N).
    !>

    TAU

    !>          TAU is DOUBLE PRECISION array, dimension (min(M,N))
    !>          The scalar factors of the elementary reflectors, as returned
    !>          by DGEQRF.
    !>

    WORK

    !>          WORK is DOUBLE PRECISION array, dimension (LWORK)
    !>

    LWORK

    !>          LWORK is INTEGER
    !>          The dimension of the array WORK.
    !>

    RWORK

    !>          RWORK is DOUBLE PRECISION array, dimension (M)
    !>

    RESULT

    !>          RESULT is DOUBLE PRECISION array, dimension (2)
    !>          The test ratios:
    !>          RESULT(1) = norm( R - Q'*A ) / ( M * norm(A) * EPS )
    !>          RESULT(2) = norm( I - Q'*Q ) / ( M * EPS )
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 124 of file dqrt01.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.