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

NAME
       SRC/sppcon.f

SYNOPSIS
   Functions/Subroutines
       subroutine sppcon (uplo, n, ap, anorm, rcond, work, iwork, info)
           SPPCON

Function/Subroutine Documentation
   subroutine sppcon (character uplo, integer n, real, dimension( * ) ap, real
       anorm, real rcond, real, dimension( * ) work, integer, dimension( * )
       iwork, integer info)
       SPPCON

       Purpose:


           !>
           !> SPPCON estimates the reciprocal of the condition number (in the
           !> 1-norm) of a real symmetric positive definite packed matrix using
           !> the Cholesky factorization A = U**T*U or A = L*L**T computed by
           !> SPPTRF.
           !>
           !> 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
           !>          = 'U':  Upper triangle of A is stored;
           !>          = 'L':  Lower triangle of A is stored.
           !>

           N

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

           AP

           !>          AP is REAL array, dimension (N*(N+1)/2)
           !>          The triangular factor U or L from the Cholesky factorization
           !>          A = U**T*U or A = L*L**T, packed columnwise in a linear
           !>          array.  The j-th column of U or L is stored in the array AP
           !>          as follows:
           !>          if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
           !>          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.
           !>

           ANORM

           !>          ANORM is REAL
           !>          The 1-norm (or infinity-norm) of the symmetric matrix A.
           !>

           RCOND

           !>          RCOND is REAL
           !>          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 REAL 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 117 of file sppcon.f.

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

LAPACK                          Version 3.12.0                 SRC/sppcon.f(3)