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

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