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

NAME
       SRC/dtrcon.f

SYNOPSIS
   Functions/Subroutines
       subroutine dtrcon (norm, uplo, diag, n, a, lda, rcond, work, iwork,
           info)
           DTRCON

Function/Subroutine Documentation
   subroutine dtrcon (character norm, character uplo, character diag, integer
       n, double precision, dimension( lda, * ) a, integer lda, double
       precision rcond, double precision, dimension( * ) work, integer,
       dimension( * ) iwork, integer info)
       DTRCON

       Purpose:


           !>
           !> DTRCON estimates the reciprocal of the condition number of a
           !> triangular matrix A, in either the 1-norm or the infinity-norm.
           !>
           !> The norm of A is computed and an estimate is obtained for
           !> norm(inv(A)), then the reciprocal of the condition number is
           !> computed as
           !>    RCOND = 1 / ( norm(A) * norm(inv(A)) ).
           !>

       Parameters
           NORM

           !>          NORM is CHARACTER*1
           !>          Specifies whether the 1-norm condition number or the
           !>          infinity-norm condition number is required:
           !>          = '1' or 'O':  1-norm;
           !>          = 'I':         Infinity-norm.
           !>

           UPLO

           !>          UPLO is CHARACTER*1
           !>          = 'U':  A is upper triangular;
           !>          = 'L':  A is lower triangular.
           !>

           DIAG

           !>          DIAG is CHARACTER*1
           !>          = 'N':  A is non-unit triangular;
           !>          = 'U':  A is unit triangular.
           !>

           N

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

           A

           !>          A is DOUBLE PRECISION array, dimension (LDA,N)
           !>          The triangular matrix A.  If UPLO = 'U', the leading N-by-N
           !>          upper triangular part of the array A contains the upper
           !>          triangular matrix, and the strictly lower triangular part of
           !>          A is not referenced.  If UPLO = 'L', the leading N-by-N lower
           !>          triangular part of the array A contains the lower triangular
           !>          matrix, and the strictly upper triangular part of A is not
           !>          referenced.  If DIAG = 'U', the diagonal elements of A are
           !>          also not referenced and are assumed to be 1.
           !>

           LDA

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

           RCOND

           !>          RCOND is DOUBLE PRECISION
           !>          The reciprocal of the condition number of the matrix A,
           !>          computed as RCOND = 1/(norm(A) * norm(inv(A))).
           !>

           WORK

           !>          WORK is DOUBLE PRECISION array, dimension (3*N)
           !>

           IWORK

           !>          IWORK is INTEGER array, dimension (N)
           !>

           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.

       Definition at line 135 of file dtrcon.f.

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

LAPACK                          Version 3.12.0                 SRC/dtrcon.f(3)