view src/samer/functions/Power.java @ 0:bf79fb79ee13

Initial Mercurial check in.

/*
 *	Copyright (c) 2000, Samer Abdallah, King's College London.
 *	All rights reserved.
 *
 *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
 *	without even the implied warranty of MERCHANTABILITY or 
 *	FITNESS FOR A PARTICULAR PURPOSE.
 */

package samer.functions;
import  samer.core.types.*;
import  samer.maths.*;
import  samer.core.*;

public class Power extends Function implements DoubleModel
{	
	double k;

	public Power(double k) { this.k=k; }

	public void set(double k) { this.k=k; }
	public double get() { return k; }
	
	public double apply(double t) { return Math.pow(t,k); }
	public void apply(double [] x) {
		for (int i=0; i<x.length; i++) x[i]=Math.pow(x[i],k);
	}
	public void apply(double [] x, double [] y) {
		for (int i=0; i<x.length; i++) y[i]=Math.pow(x[i],k);
	}
	public String format(String arg) { return arg+"^"+X.string(k); }

	public Function derivative() { 
		if (k==3) return new Quadratic(3,0,0);
		else if (k==2) return new Linear(2,0);
		else if (k==1) return new Constant(1);
		else return new ScaledFunction(new Power(k-1),k); 
	}
	public Function inverse() { return new Power(1/k); }
}