SRC/dsytri2.f(3)           Library Functions Manual           SRC/dsytri2.f(3)

NAME
       SRC/dsytri2.f

SYNOPSIS
   Functions/Subroutines
       subroutine dsytri2 (uplo, n, a, lda, ipiv, work, lwork, info)
           DSYTRI2

Function/Subroutine Documentation
   subroutine dsytri2 (character uplo, integer n, double precision, dimension(
       lda, * ) a, integer lda, integer, dimension( * ) ipiv, double
       precision, dimension( * ) work, integer lwork, integer info)
       DSYTRI2

       Purpose:


           !>
           !> DSYTRI2 computes the inverse of a DOUBLE PRECISION symmetric indefinite matrix
           !> A using the factorization A = U*D*U**T or A = L*D*L**T computed by
           !> DSYTRF. DSYTRI2 sets the LEADING DIMENSION of the workspace
           !> before calling DSYTRI2X 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 DOUBLE PRECISION 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 DSYTRF.
           !>
           !>          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 DSYTRF.
           !>

           WORK

           !>          WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK))
           !>

           LWORK

           !>          LWORK is INTEGER
           !>          The dimension of the array WORK.
           !>          If N = 0, LWORK >= 1, else LWORK >= (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 dsytri2.f.

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

LAPACK                          Version 3.12.0                SRC/dsytri2.f(3)