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DLACON(1)	    LAPACK auxiliary routine (version 3.2)	     DLACON(1)

NAME
       DLACON - estimates the 1-norm of a square, real matrix A

SYNOPSIS
       SUBROUTINE DLACON( N, V, X, ISGN, EST, KASE )

	   INTEGER	  KASE, N

	   DOUBLE	  PRECISION EST

	   INTEGER	  ISGN( * )

	   DOUBLE	  PRECISION V( * ), X( * )

PURPOSE
       DLACON estimates the 1-norm of a square, real matrix A.	Reverse commu‐
       nication is used for evaluating matrix-vector products.

ARGUMENTS
       N      (input) INTEGER
	      The order of the matrix.	N >= 1.

       V      (workspace) DOUBLE PRECISION array, dimension (N)
	      On the final return, V = A*W,  where  EST =  norm(V)/norm(W)  (W
	      is not returned).

       X      (input/output) DOUBLE PRECISION array, dimension (N)
	      On  an  intermediate  return,  X should be overwritten by A * X,
	      if KASE=1, A' * X,  if KASE=2, and DLACON must be re-called with
	      all the other parameters unchanged.

       ISGN   (workspace) INTEGER array, dimension (N)

       EST    (input/output) DOUBLE PRECISION
	      On  entry	 with  KASE  =	1  or  2  and  JUMP = 3, EST should be
	      unchanged from the previous call to DLACON.  On exit, EST is  an
	      estimate (a lower bound) for norm(A).

       KASE   (input/output) INTEGER
	      On the initial call to DLACON, KASE should be 0.	On an interme‐
	      diate return, KASE will be 1 or 2, indicating whether  X	should
	      be  overwritten  by  A * X  or A' * X.  On the final return from
	      DLACON, KASE will again be 0.

FURTHER DETAILS
       Contributed by Nick Higham, University of Manchester.
       Originally named SONEST, dated March 16, 1988.
       Reference: N.J. Higham, "FORTRAN codes for estimating the one-norm of a
       real or complex matrix, with applications to condition estimation", ACM
       Trans. Math. Soft., vol. 14, no. 4, pp. 381-396, December 1988.

 LAPACK auxiliary routine (versioNovember 2008			     DLACON(1)
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