LAPACK 3.11.0
LAPACK: Linear Algebra PACKage

◆ csyconv()

subroutine csyconv ( character  UPLO,
character  WAY,
integer  N,
complex, dimension( lda, * )  A,
integer  LDA,
integer, dimension( * )  IPIV,
complex, dimension( * )  E,
integer  INFO 
)

CSYCONV

Download CSYCONV + dependencies [TGZ] [ZIP] [TXT]

Purpose:
 CSYCONV 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
[in]UPLO
          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.
[in]WAY
          WAY is CHARACTER*1
          = 'C': Convert
          = 'R': Revert
[in]N
          N is INTEGER
          The order of the matrix A.  N >= 0.
[in,out]A
          A is COMPLEX array, dimension (LDA,N)
          The block diagonal matrix D and the multipliers used to
          obtain the factor U or L as computed by CSYTRF.
[in]LDA
          LDA is INTEGER
          The leading dimension of the array A.  LDA >= max(1,N).
[in]IPIV
          IPIV is INTEGER array, dimension (N)
          Details of the interchanges and the block structure of D
          as determined by CSYTRF.
[out]E
          E is COMPLEX array, dimension (N)
          E stores the supdiagonal/subdiagonal of the symmetric 1-by-1
          or 2-by-2 block diagonal matrix D in LDLT.
[out]INFO
          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.