SSYCONV(3)     LAPACK routine of NEC Numeric Library Collection     SSYCONV(3)



NAME
       SSYCONV

SYNOPSIS
       SUBROUTINE SSYCONV (UPLO, WAY, N, A, LDA, IPIV, WORK, INFO)



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




ARGUMENTS
           UPLO      (input)
                     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       (input)
                     WAY is CHARACTER*1
                     = 'C': Convert
                     = 'R': Revert

           N         (input)
                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           A         (input)
                     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       (input)
                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,N).

           IPIV      (input)
                     IPIV is INTEGER array, dimension (N)
                     Details of the interchanges and the block structure of D
                     as determined by SSYTRF.

           WORK      (output)
                     WORK is REAL array, dimension (N)

           INFO      (output)
                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value



LAPACK routine                  31 October 2017                     SSYCONV(3)