DBDT02
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
November 2006
Purpose
DBDT02 tests the change of basis C = U' * B by computing the residual
RESID = norm( B - U * C ) / ( max(m,n) * norm(B) * EPS ),
where B and C are M by N matrices, U is an M by M orthogonal matrix,
and EPS is the machine precision.
RESID = norm( B - U * C ) / ( max(m,n) * norm(B) * EPS ),
where B and C are M by N matrices, U is an M by M orthogonal matrix,
and EPS is the machine precision.
Arguments
| M |
(input) INTEGER
The number of rows of the matrices B and C and the order of
the matrix Q. |
| N |
(input) INTEGER
The number of columns of the matrices B and C.
|
| B |
(input) DOUBLE PRECISION array, dimension (LDB,N)
The m by n matrix B.
|
| LDB |
(input) INTEGER
The leading dimension of the array B. LDB >= max(1,M).
|
| C |
(input) DOUBLE PRECISION array, dimension (LDC,N)
The m by n matrix C, assumed to contain U' * B.
|
| LDC |
(input) INTEGER
The leading dimension of the array C. LDC >= max(1,M).
|
| U |
(input) DOUBLE PRECISION array, dimension (LDU,M)
The m by m orthogonal matrix U.
|
| LDU |
(input) INTEGER
The leading dimension of the array U. LDU >= max(1,M).
|
| WORK |
(workspace) DOUBLE PRECISION array, dimension (M)
|
| RESID |
(output) DOUBLE PRECISION
RESID = norm( B - U * C ) / ( max(m,n) * norm(B) * EPS ),
|