SRC/chetri2.f(3)           Library Functions Manual           SRC/chetri2.f(3)

NAME
       SRC/chetri2.f

SYNOPSIS
   Functions/Subroutines
       subroutine chetri2 (uplo, n, a, lda, ipiv, work, lwork, info)
           CHETRI2

Function/Subroutine Documentation
   subroutine chetri2 (character uplo, integer n, complex, dimension( lda, * )
       a, integer lda, integer, dimension( * ) ipiv, complex, dimension( * )
       work, integer lwork, integer info)
       CHETRI2

       Purpose:


            CHETRI2 computes the inverse of a COMPLEX hermitian indefinite matrix
            A using the factorization A = U*D*U**T or A = L*D*L**T computed by
            CHETRF. CHETRI2 set the LEADING DIMENSION of the workspace
            before calling CHETRI2X that actually computes the inverse.

       Parameters
           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.

           N

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

           A

                     A is COMPLEX array, dimension (LDA,N)
                     On entry, the block diagonal matrix D and the multipliers
                     used to obtain the factor U or L as computed by CHETRF.

                     On exit, if INFO = 0, the (symmetric) inverse of the original
                     matrix.  If UPLO = 'U', the upper triangular part of the
                     inverse is formed and the part of A below the diagonal is not
                     referenced; if UPLO = 'L' the lower triangular part of the
                     inverse is formed and the part of A above the diagonal is
                     not referenced.

           LDA

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

           IPIV

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

           WORK

                     WORK is COMPLEX array, dimension (N+NB+1)*(NB+3)

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.
                     WORK is size >= (N+NB+1)*(NB+3)
                     If LWORK = -1, then a workspace query is assumed; the routine
                      calculates:
                         - the optimal size of the WORK array, returns
                     this value as the first entry of the WORK array,
                         - and no error message related to LWORK is issued by XERBLA.

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value
                     > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its
                          inverse could not be computed.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 126 of file chetri2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                SRC/chetri2.f(3)