TESTING/LIN/dqlt03.f(3) Library Functions Manual TESTING/LIN/dqlt03.f(3) NAME TESTING/LIN/dqlt03.f SYNOPSIS Functions/Subroutines subroutine dqlt03 (m, n, k, af, c, cc, q, lda, tau, work, lwork, rwork, result) DQLT03 Function/Subroutine Documentation subroutine dqlt03 (integer m, integer n, integer k, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) c, double precision, dimension( lda, * ) cc, double precision, dimension( lda, * ) q, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( * ) result) DQLT03 Purpose: DQLT03 tests DORMQL, which computes Q*C, Q'*C, C*Q or C*Q'. DQLT03 compares the results of a call to DORMQL with the results of forming Q explicitly by a call to DORGQL and then performing matrix multiplication by a call to DGEMM. Parameters M M is INTEGER The order of the orthogonal matrix Q. M >= 0. N N is INTEGER The number of rows or columns of the matrix C; C is m-by-n if Q is applied from the left, or n-by-m if Q is applied from the right. N >= 0. K K is INTEGER The number of elementary reflectors whose product defines the orthogonal matrix Q. M >= K >= 0. AF AF is DOUBLE PRECISION array, dimension (LDA,N) Details of the QL factorization of an m-by-n matrix, as returned by DGEQLF. See SGEQLF for further details. C C is DOUBLE PRECISION array, dimension (LDA,N) CC CC is DOUBLE PRECISION array, dimension (LDA,N) Q Q is DOUBLE PRECISION array, dimension (LDA,M) LDA LDA is INTEGER The leading dimension of the arrays AF, C, CC, and Q. TAU TAU is DOUBLE PRECISION array, dimension (min(M,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 length of WORK. LWORK must be at least M, and should be M*NB, where NB is the blocksize for this environment. RWORK RWORK is DOUBLE PRECISION array, dimension (M) RESULT RESULT is DOUBLE PRECISION array, dimension (4) The test ratios compare two techniques for multiplying a random matrix C by an m-by-m orthogonal matrix Q. RESULT(1) = norm( Q*C - Q*C ) / ( M * norm(C) * EPS ) RESULT(2) = norm( C*Q - C*Q ) / ( M * norm(C) * EPS ) RESULT(3) = norm( Q'*C - Q'*C )/ ( M * norm(C) * EPS ) RESULT(4) = norm( C*Q' - C*Q' )/ ( M * norm(C) * EPS ) Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 134 of file dqlt03.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/dqlt03.f(3)