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.core.util;
samer@0: 
samer@0: /**
samer@0: 	This class maps a given interval of real numbers
samer@0: 	to the interval [0,1], returning either the real
samer@0: 	number, or converting it to an integer between 0
samer@0: 	and a given value (defaults to 256). 
samer@0:  */
samer@0: 
samer@0: public class LogMap extends IMap
samer@0: {
samer@0: 	public LogMap() { this(0.001,1.0,256); }
samer@0: 	public LogMap(int m) { this(0.001,1.0,m); }
samer@0: 	public LogMap(double t1, double t2) { this(t1,t2,256); }
samer@0: 	public LogMap(double t1, double t2, int m) { setDomain(t1,t2); setIntRange(m); }
samer@0: 
samer@0: 	public double getDomainMin() { return Math.exp(super.getDomainMin()); }
samer@0: 	public double getDomainMax() { return Math.exp(super.getDomainMax()); }
samer@0: 	public void setDomain( double t1, double t2)	{
samer@0: 		if (t1<0 || t2<0) throw new Error("Bad domain for log map");
samer@0: 		super.setDomain( Math.log(t1), Math.log(t2));
samer@0: 	}
samer@0: 
samer@0: 	private static double log(double t) { return t>0 ? Math.log(t) : Double.NEGATIVE_INFINITY; }
samer@0: 	public final double map( double t) { return super.map(log(t)); }
samer@0: 	public final int clipInt( double t) { return super.clipInt(log(t)); }
samer@0: 	public final int toInt( double t) { return super.toInt(log(t)); }
samer@0: 	public double inverse(double t) { return Math.exp(super.inverse(t)); }
samer@0: 	public double inverseFromInt(int i) { return Math.exp(super.inverseFromInt(i)); }
samer@0: }
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