/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2010 Neil C Smith.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 3 for more details.
*
* You should have received a copy of the GNU General Public License version 3
* along with this work; if not, see http://www.gnu.org/licenses/
*
*
* Please visit http://neilcsmith.net if you need additional information or
* have any questions.
*
*/
package net.neilcsmith.praxis.util.interpolation;
/**
*
* @author Neil C Smith
*/
public class ExponentialInterpolator implements Interpolator {
private final static ExponentialInterpolator instance = new ExponentialInterpolator();
private final double Em1 = Math.E - 1;
private ExponentialInterpolator() {}
public double interpolate(double value) {
if (value <= 0) {
return 0;
} else if (value >= 1) {
return 1;
} else {
// return Math.log1p(value * Em1);
return Math.expm1(value) / Em1;
}
}
public double reverseInterpolate(double value) {
if (value <= 0) {
return 0;
} else if (value >= 1) {
return 1;
} else {
// return Math.expm1(value) / Em1;
return Math.log1p(value * Em1);
}
}
public static ExponentialInterpolator getInstance() {
return instance;
}
}
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