ExponentialDistribution.java

/*
 * chombo: Hadoop Map Reduce utility
 * Author: Pranab Ghosh
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you
 * may not use this file except in compliance with the License. You may
 * obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0 
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

package org.chombo.util;

public class ExponentialDistribution implements ProbabilityDistribution{
	private double beta;
	
	/**
	 * @param mean
	 */
	public ExponentialDistribution(double mean) {
		beta = 1.0 / mean;
	}
	
	/* (non-Javadoc)
	 * @see org.chombo.util.ProbabilityDistribution#getDistr(double)
	 */
	public double getDistr(double ord) {
		double distr = 1.0 - Math.exp(-beta * ord);
		return distr;
	}	
}