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/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dqlt02.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dqlt02.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/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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Version 3.12.0 LAPACK