DSYCON(l)		LAPACK routine (version	1.1)		    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 condi-
  tion 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 triangular, 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 deter-
	  mined	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, computed as
	  RCOND	= 1/(ANORM * AINVNM), where AINVNM is an estimate 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