LAPACK 3.11.0
LAPACK: Linear Algebra PACKage

◆ clatsp()

subroutine clatsp ( character  UPLO,
integer  N,
complex, dimension( * )  X,
integer, dimension( * )  ISEED 
)

CLATSP

Purpose:
 CLATSP generates a special test matrix for the complex symmetric
 (indefinite) factorization for packed matrices.  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
[in]UPLO
          UPLO is CHARACTER
          Specifies whether the generated matrix is to be upper or
          lower triangular.
          = 'U':  Upper triangular
          = 'L':  Lower triangular
[in]N
          N is INTEGER
          The dimension of the matrix to be generated.
[out]X
          X is COMPLEX array, dimension (N*(N+1)/2)
          The generated matrix in packed storage format.  The matrix
          consists of 3x3 and 2x2 diagonal blocks which result in the
          pivot sequence given above.  The matrix outside these
          diagonal blocks is zero.
[in,out]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.