dlacon.f(3)							      LAPACK							       dlacon.f(3)

NAME

       dlacon.f -

SYNOPSIS

   Functions/Subroutines
       subroutine dlacon (N, V, X, ISGN, EST, KASE)
	   DLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

Function/Subroutine Documentation
   subroutine dlacon (integerN, double precision, dimension( * )V, double precision, dimension( * )X, integer, dimension( * )ISGN, double
       precisionEST, integerKASE)
       DLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

       Purpose:

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

       Parameters:
	   N

		     N is INTEGER
		    The order of the matrix.  N >= 1.

	   V

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

	   X

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

	   ISGN

		     ISGN is INTEGER array, dimension (N)

	   EST

		     EST is 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

		     KASE is INTEGER
		    On the initial call to DLACON, KASE should be 0.
		    On an intermediate return, KASE will be 1 or 2, indicating
		    whether X should be overwritten by A * X  or A**T * X.
		    On the final return from DLACON, KASE will again be 0.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Contributors:
	   Nick Higham, University of Manchester.
	    Originally named SONEST, dated March 16, 1988.

       References:
	   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.

       Definition at line 116 of file dlacon.f.

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

Version 3.4.2							  Tue Sep 25 2012						       dlacon.f(3)