ZLATSY
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
November 2006
Purpose
ZLATSY generates a special test matrix for the complex symmetric
(indefinite) factorization. The pivot blocks of the generated matrix
will be in the following order:
2x2 pivot block, non diagonalizable
1x1 pivot block
2x2 pivot block, diagonalizable
(cycle repeats)
A row interchange is required for each non-diagonalizable 2x2 block.
(indefinite) factorization. The pivot blocks of the generated matrix
will be in the following order:
2x2 pivot block, non diagonalizable
1x1 pivot block
2x2 pivot block, diagonalizable
(cycle repeats)
A row interchange is required for each non-diagonalizable 2x2 block.
Arguments
| UPLO |
(input) CHARACTER
Specifies whether the generated matrix is to be upper or
lower triangular. = 'U': Upper triangular = 'L': Lower triangular |
| N |
(input) INTEGER
The dimension of the matrix to be generated.
|
| X |
(output) COMPLEX*16 array, dimension (LDX,N)
The generated matrix, consisting of 3x3 and 2x2 diagonal
blocks which result in the pivot sequence given above. The matrix outside of these diagonal blocks is zero. |
| LDX |
(input) INTEGER
The leading dimension of the array X.
|
| ISEED |
(input/output) INTEGER array, dimension (4)
On entry, the seed for the random number generator. The last
of the four integers must be odd. (modified on exit) |