TESTING/LIN/dlqt02.f(3) Library Functions Manual TESTING/LIN/dlqt02.f(3) NAME TESTING/LIN/dlqt02.f SYNOPSIS Functions/Subroutines subroutine dlqt02 (m, n, k, a, af, q, l, lda, tau, work, lwork, rwork, result) DLQT02 Function/Subroutine Documentation subroutine dlqt02 (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) DLQT02 Purpose: DLQT02 tests DORGLQ, which generates an m-by-n matrix Q with orthonormal rows that is defined as the product of k elementary reflectors. Given the LQ factorization of an m-by-n matrix A, DLQT02 generates the orthogonal matrix Q defined by the factorization of the first k rows of A; it compares L(1:k,1:m) with A(1:k,1:n)*Q(1:m,1:n)', and checks that the rows 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. N >= M >= 0. K K is INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. A A is DOUBLE PRECISION array, dimension (LDA,N) The m-by-n matrix A which was factorized by DLQT01. AF AF is DOUBLE PRECISION array, dimension (LDA,N) Details of the LQ factorization of A, as returned by DGELQF. See DGELQF for further details. Q Q is DOUBLE PRECISION array, dimension (LDA,N) L L is DOUBLE PRECISION array, dimension (LDA,M) LDA LDA is INTEGER The leading dimension of the arrays A, AF, Q and L. LDA >= N. TAU TAU is DOUBLE PRECISION array, dimension (M) The scalar factors of the elementary reflectors corresponding to the LQ 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 - A*Q' ) / ( N * norm(A) * EPS ) RESULT(2) = norm( I - Q*Q' ) / ( N * EPS ) Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 133 of file dlqt02.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/dlqt02.f(3)