samer@0: /*
samer@0:  *	Copyright (c) 2000, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or 
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.maths.opt;
samer@0: 
samer@0: /**
samer@0: 	This is a function interface that is designed
samer@0: 	to allow efficient implementations of minimisation
samer@0: 	algorithms by recognising the fact that the
samer@0: 	function and its gradient may be repeatedly 
samer@0: 	evaluated at the same point in different parts
samer@0: 	of the code - hence we can save ourselves
samer@0: 	some computation.
samer@0: 
samer@0:  */
samer@0: 
samer@0: 
samer@0: public interface Functionx
samer@0: {
samer@0: 	/** get value and gradient for supplied point */
samer@0: 	void evaluate( Datum P);
samer@0: 
samer@0: 	/** set argument to x, return value and put gradient in dx */
samer@0: 	double evaluate( double [] x, double [] grad);
samer@0: 
samer@0: 	void dispose();
samer@0: }