dlqt03.f - Man Page
TESTING/LIN/dlqt03.f
Synopsis
Functions/Subroutines
subroutine dlqt03 (m, n, k, af, c, cc, q, lda, tau, work, lwork, rwork, result)
DLQT03
Function/Subroutine Documentation
subroutine dlqt03 (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)
DLQT03
Purpose:
DLQT03 tests DORMLQ, which computes Q*C, Q'*C, C*Q or C*Q'. DLQT03 compares the results of a call to DORMLQ with the results of forming Q explicitly by a call to DORGLQ 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 LQ factorization of an m-by-n matrix, as returned by DGELQF. See SGELQF 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 LQ 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 dlqt03.f.
Author
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Referenced By
The man page dlqt03(3) is an alias of dlqt03.f(3).
Tue Nov 28 2023 12:08:43 Version 3.12.0 LAPACK