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

NAME
       SRC/dspcon.f

SYNOPSIS
   Functions/Subroutines
       subroutine dspcon (uplo, n, ap, ipiv, anorm, rcond, work, iwork, info)
           DSPCON

Function/Subroutine Documentation
   subroutine dspcon (character uplo, integer n, double precision, dimension(
       * ) ap, integer, dimension( * ) ipiv, double precision anorm, double
       precision rcond, double precision, dimension( * ) work, integer,
       dimension( * ) iwork, integer info)
       DSPCON

       Purpose:


            DSPCON estimates the reciprocal of the condition number (in the
            1-norm) of a real symmetric packed matrix A using the factorization
            A = U*D*U**T or A = L*D*L**T computed by DSPTRF.

            An estimate is obtained for norm(inv(A)), and the reciprocal of the
            condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

       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.

           AP

                     AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
                     The block diagonal matrix D and the multipliers used to
                     obtain the factor U or L as computed by DSPTRF, stored as a
                     packed triangular matrix.

           IPIV

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

           ANORM

                     ANORM is DOUBLE PRECISION
                     The 1-norm of the original matrix A.

           RCOND

                     RCOND is DOUBLE PRECISION
                     The reciprocal of the condition number of the matrix A,
                     computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
                     estimate of the 1-norm of inv(A) computed in this routine.

           WORK

                     WORK is DOUBLE PRECISION array, dimension (2*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 123 of file dspcon.f.

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

LAPACK                          Version 3.12.0                 SRC/dspcon.f(3)