SGET36
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
November 2006
Purpose
SGET36 tests STREXC, a routine for moving blocks (either 1 by 1 or
2 by 2) on the diagonal of a matrix in real Schur form. Thus, SLAEXC
computes an orthogonal matrix Q such that
Q' * T1 * Q = T2
and where one of the diagonal blocks of T1 (the one at row IFST) has
been moved to position ILST.
The test code verifies that the residual Q'*T1*Q-T2 is small, that T2
is in Schur form, and that the final position of the IFST block is
ILST (within +-1).
The test matrices are read from a file with logical unit number NIN.
2 by 2) on the diagonal of a matrix in real Schur form. Thus, SLAEXC
computes an orthogonal matrix Q such that
Q' * T1 * Q = T2
and where one of the diagonal blocks of T1 (the one at row IFST) has
been moved to position ILST.
The test code verifies that the residual Q'*T1*Q-T2 is small, that T2
is in Schur form, and that the final position of the IFST block is
ILST (within +-1).
The test matrices are read from a file with logical unit number NIN.
Arguments
| RMAX |
(output) REAL
Value of the largest test ratio.
|
| LMAX |
(output) INTEGER
Example number where largest test ratio achieved.
|
| NINFO |
(output) INTEGER array, dimension (3)
NINFO(J) is the number of examples where INFO=J.
|
| KNT |
(output) INTEGER
Total number of examples tested.
|
| NIN |
(input) INTEGER
Input logical unit number.
|