clatsy.f - Man Page

subroutine clatsy (uplo, n, x, ldx, iseed)
CLATSY

CLATSY

Purpose:

 CLATSY 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.

Parameters

UPLO

          UPLO is CHARACTER
          Specifies whether the generated matrix is to be upper or
          lower triangular.
          = 'U':  Upper triangular
          = 'L':  Lower triangular

N

          N is INTEGER
          The dimension of the matrix to be generated.

X

          X is COMPLEX 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

          LDX is INTEGER
          The leading dimension of the array X.

ISEED

          ISEED is 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)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 88 of file clatsy.f.