TESTING/LIN/dqlt02.f(3)

NAME
TESTING/LIN/dqlt02.f

SYNOPSIS

  Functions/Subroutines
subroutine dqlt02 (m, n, k, a, af, q, l, lda, tau, work, lwork, rwork, result)
DQLT02

Function/Subroutine Documentation

  subroutine dqlt02 (integer m, integer n, integer k, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) q, double precision, dimension( lda, * ) l, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( * ) result)

DQLT02

Purpose:

    !>
    !> DQLT02 tests DORGQL, which generates an m-by-n matrix Q with
    !> orthonormal columns that is defined as the product of k elementary
    !> reflectors.
    !>
    !> Given the QL factorization of an m-by-n matrix A, DQLT02 generates
    !> the orthogonal matrix Q defined by the factorization of the last k
    !> columns of A; it compares L(m-n+1:m,n-k+1:n) with
    !> Q(1:m,m-n+1:m)'*A(1:m,n-k+1:n), and checks that the columns of Q are
    !> orthonormal.
    !>

Parameters
    M

    !>          M is INTEGER
    !>          The number of rows of the matrix Q to be generated.  M >= 0.
    !>

    N

    !>          N is INTEGER
    !>          The number of columns of the matrix Q to be generated.
    !>          M >= N >= 0.
    !>

    K

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

    A

    !>          A is DOUBLE PRECISION array, dimension (LDA,N)
    !>          The m-by-n matrix A which was factorized by DQLT01.
    !>

    AF

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

    Q

    !>          Q is DOUBLE PRECISION array, dimension (LDA,N)
    !>

    L

    !>          L is DOUBLE PRECISION array, dimension (LDA,N)
    !>

    LDA

    !>          LDA is INTEGER
    !>          The leading dimension of the arrays A, AF, Q and L. LDA >= M.
    !>

    TAU

    !>          TAU is DOUBLE PRECISION array, dimension (N)
    !>          The scalar factors of the elementary reflectors corresponding
    !>          to the QL factorization in AF.
    !>

    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( L - 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 134 of file dqlt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.