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;
samer@0: 
samer@0: public class Identity extends Function
samer@0: {
samer@0: 	public void apply(double [] u, double [] y) { System.arraycopy(u,0,y,0,u.length); }
samer@0: 	public void apply(double [] u) { return; }
samer@0: 	public double apply(double t) { return t; }
samer@0: 	public String format(String arg) { return arg; }
samer@0: 	public Function inverse() { return this; }
samer@0: 	public Function derivative() { return new Constant(1); }
samer@0: }