drqt03.f - Man Page
TESTING/LIN/drqt03.f
Synopsis
Functions/Subroutines
subroutine drqt03 (m, n, k, af, c, cc, q, lda, tau, work, lwork, rwork, result)
DRQT03
Function/Subroutine Documentation
subroutine drqt03 (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)
DRQT03
Purpose:
DRQT03 tests DORMRQ, which computes Q*C, Q'*C, C*Q or C*Q'. DRQT03 compares the results of a call to DORMRQ with the results of forming Q explicitly by a call to DORGRQ and then performing matrix multiplication by a call to DGEMM.
- Parameters
M
M is INTEGER The number of rows or columns of the matrix C; C is n-by-m if Q is applied from the left, or m-by-n if Q is applied from the right. M >= 0.
N
N is INTEGER The order of the orthogonal matrix Q. N >= 0.
K
K is INTEGER The number of elementary reflectors whose product defines the orthogonal matrix Q. N >= K >= 0.
AF
AF is DOUBLE PRECISION array, dimension (LDA,N) Details of the RQ factorization of an m-by-n matrix, as returned by DGERQF. See SGERQF 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,N)
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 RQ 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 n-by-n orthogonal matrix Q. RESULT(1) = norm( Q*C - Q*C ) / ( N * norm(C) * EPS ) RESULT(2) = norm( C*Q - C*Q ) / ( N * norm(C) * EPS ) RESULT(3) = norm( Q'*C - Q'*C )/ ( N * norm(C) * EPS ) RESULT(4) = norm( C*Q' - C*Q' )/ ( N * norm(C) * EPS )
- Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 134 of file drqt03.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Referenced By
The man page drqt03(3) is an alias of drqt03.f(3).
Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK