CQRT03
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
November 2006
Purpose
CQRT03 tests CUNMQR, which computes Q*C, Q'*C, C*Q or C*Q'.
CQRT03 compares the results of a call to CUNMQR with the results of
forming Q explicitly by a call to CUNGQR and then performing matrix
multiplication by a call to CGEMM.
CQRT03 compares the results of a call to CUNMQR with the results of
forming Q explicitly by a call to CUNGQR and then performing matrix
multiplication by a call to CGEMM.
Arguments
| M |
(input) INTEGER
The order of the orthogonal matrix Q. M >= 0.
|
| N |
(input) 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 |
(input) INTEGER
The number of elementary reflectors whose product defines the
orthogonal matrix Q. M >= K >= 0. |
| AF |
(input) COMPLEX array, dimension (LDA,N)
Details of the QR factorization of an m-by-n matrix, as
returnedby CGEQRF. See CGEQRF for further details. |
| C |
(workspace) COMPLEX array, dimension (LDA,N)
|
| CC |
(workspace) COMPLEX array, dimension (LDA,N)
|
| Q |
(workspace) COMPLEX array, dimension (LDA,M)
|
| LDA |
(input) INTEGER
The leading dimension of the arrays AF, C, CC, and Q.
|
| TAU |
(input) COMPLEX array, dimension (min(M,N))
The scalar factors of the elementary reflectors corresponding
to the QR factorization in AF. |
| WORK |
(workspace) COMPLEX array, dimension (LWORK)
|
| LWORK |
(input) 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 |
(workspace) REAL array, dimension (M)
|
| RESULT |
(output) REAL 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 ) |