slacon(l) [redhat man page]

SLACON(l)								 )								 SLACON(l)

NAME

       SLACON - estimate the 1-norm of a square, real matrix A

SYNOPSIS

       SUBROUTINE SLACON( N, V, X, ISGN, EST, KASE )

	   INTEGER	  KASE, N

	   REAL 	  EST

	   INTEGER	  ISGN( * )

	   REAL 	  V( * ), X( * )

PURPOSE

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

ARGUMENTS

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

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

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

       ISGN   (workspace) INTEGER array, dimension (N)

       EST    (output) REAL
	      An estimate (a lower bound) for norm(A).

       KASE   (input/output) INTEGER
	      On the initial call to SLACON, 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' * X.	On the final return from SLACON, 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 version 3.0						   15 June 2000 							 SLACON(l)

slacon.f(3)							      LAPACK							       slacon.f(3)

NAME

       slacon.f -

SYNOPSIS

   Functions/Subroutines
       subroutine slacon (N, V, X, ISGN, EST, KASE)
	   SLACON

Function/Subroutine Documentation
   subroutine slacon (integerN, real, dimension( * )V, real, dimension( * )X, integer, dimension( * )ISGN, realEST, integerKASE)
       SLACON

       Purpose:

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

	   X

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

	   ISGN

		     ISGN is INTEGER array, dimension (N)

	   EST

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

	   KASE

		     KASE is INTEGER
		    On the initial call to SLACON, 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 SLACON, KASE will again be 0.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       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 slacon.f.

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

Version 3.4.1							  Sun May 26 2013						       slacon.f(3)