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DSYCON(l)			       )			     DSYCON(l)

NAME
       DSYCON  -  estimate  the	 reciprocal  of	 the  condition number (in the
       1-norm) of a real symmetric  matrix  A  using  the  factorization  A  =
       U*D*U**T or A = L*D*L**T computed by DSYTRF

SYNOPSIS
       SUBROUTINE DSYCON( UPLO,	 N,  A,	 LDA, IPIV, ANORM, RCOND, WORK, IWORK,
			  INFO )

	   CHARACTER	  UPLO

	   INTEGER	  INFO, LDA, N

	   DOUBLE	  PRECISION ANORM, RCOND

	   INTEGER	  IPIV( * ), IWORK( * )

	   DOUBLE	  PRECISION A( LDA, * ), WORK( * )

PURPOSE
       DSYCON estimates the reciprocal of the condition number (in the 1-norm)
       of  a real symmetric matrix A using the factorization A = U*D*U**T or A
       =  L*D*L**T  computed  by  DSYTRF.   An	estimate   is	obtained   for
       norm(inv(A)), and the reciprocal of the condition number is computed as
       RCOND = 1 / (ANORM * norm(inv(A))).

ARGUMENTS
       UPLO    (input) CHARACTER*1
	       Specifies whether the details of the factorization  are	stored
	       as an upper or lower triangular matrix.	= 'U':	Upper triangu‐
	       lar, form is A = U*D*U**T;
	       = 'L':  Lower triangular, form is A = L*D*L**T.

       N       (input) INTEGER
	       The order of the matrix A.  N >= 0.

       A       (input) DOUBLE PRECISION array, dimension (LDA,N)
	       The block diagonal matrix D and the multipliers used to	obtain
	       the factor U or L as computed by DSYTRF.

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

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

       ANORM   (input) DOUBLE PRECISION
	       The 1-norm of the original matrix A.

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

       WORK    (workspace) DOUBLE PRECISION array, dimension (2*N)

       IWORK	(workspace) INTEGER array, dimension (N)

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value

LAPACK version 3.0		 15 June 2000			     DSYCON(l)
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