zlacn2.f(3)							      LAPACK							       zlacn2.f(3)

NAME

       zlacn2.f -

SYNOPSIS

   Functions/Subroutines
       subroutine zlacn2 (N, V, X, EST, KASE, ISAVE)
	   ZLACN2 estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

Function/Subroutine Documentation
   subroutine zlacn2 (integerN, complex*16, dimension( * )V, complex*16, dimension( * )X, double precisionEST, integerKASE, integer, dimension( 3
       )ISAVE)
       ZLACN2 estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

       Purpose:

	    ZLACN2 estimates the 1-norm of a square, complex 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 COMPLEX*16 array, dimension (N)
		    On the final return, V = A*W,  where  EST = norm(V)/norm(W)
		    (W is not returned).

	   X

		     X is COMPLEX*16 array, dimension (N)
		    On an intermediate return, X should be overwritten by
			  A * X,   if KASE=1,
			  A**H * X,  if KASE=2,
		    where A**H is the conjugate transpose of A, and ZLACN2 must be
		    re-called with all the other parameters unchanged.

	   EST

		     EST is DOUBLE PRECISION
		    On entry with KASE = 1 or 2 and ISAVE(1) = 3, EST should be
		    unchanged from the previous call to ZLACN2.
		    On exit, EST is an estimate (a lower bound) for norm(A).

	   KASE

		     KASE is INTEGER
		    On the initial call to ZLACN2, 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**H * X.
		    On the final return from ZLACN2, KASE will again be 0.

	   ISAVE

		     ISAVE is INTEGER array, dimension (3)
		    ISAVE is used to save variables between calls to ZLACN2

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Further Details:

	     Originally named CONEST, dated March 16, 1988.

	     Last modified:  April, 1999

	     This is a thread safe version of ZLACON, which uses the array ISAVE
	     in place of a SAVE statement, as follows:

		ZLACON	   ZLACN2
		 JUMP	  ISAVE(1)
		 J	  ISAVE(2)
		 ITER	  ISAVE(3)

       Contributors:
	   Nick Higham, University of Manchester

       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 134 of file zlacn2.f.

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

Version 3.4.2							  Tue Sep 25 2012						       zlacn2.f(3)