SYCONV - 5.2 English - 68552

SYCONV convert A given by TRF into L and D and vice-versa.

Purpose:

  SYCONV convert A given by TRF into L and D and vice-versa.
  Get Non-diag elements of D (returned in workspace) and
  apply or reverse permutation done in TRF.

Parameters:

• UPLO – [in]

  UPLO is CHARACTER*1

  Specifies whether the details of the factorization are stored as an upper or lower triangular matrix.

  = ‘U’: Upper triangular, form is A = U*D*U**T;

  = ‘L’: Lower triangular, form is A = L*D*L**T.

• WAY – [in]

  WAY is CHARACTER*1

  = ‘C’: Convert

  = ‘R’: Revert

• N – [in]

  N is INTEGER

  The order of the matrix A. N >= 0.

• A – [inout]

  A is REAL array, dimension (LDA,N)

  The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by SSYTRF.

• LDA – [in]

  LDA is INTEGER

  The leading dimension of the array A. LDA >= fla_max(1,N).

• IPIV – [in]

  IPIV is INTEGER array, dimension (N)

  Details of the interchanges and the block structure of D as determined by SSYTRF.

• E – [out]

  E is REAL array, dimension (N)

  E stores the supdiagonal/subdiagonal of the symmetric 1-by-1 or 2-by-2 block diagonal matrix D in LDLT.

• INFO – [out]

  INFO is INTEGER

  = 0: successful exit

  < 0: if INFO = -i, the i-th argument had an illegal value