CalcProbability.java

/*
 * Encog(tm) Core v3.4 - Java Version
 * http://www.heatonresearch.com/encog/
 * https://github.com/encog/encog-java-core
 
 * Copyright 2008-2016 Heaton Research, Inc.
 *
 * 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.
 *   
 * For more information on Heaton Research copyrights, licenses 
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */
package org.encog.mathutil.probability;

import java.util.ArrayList;
import java.util.List;

public class CalcProbability {
	private final List<Integer> classes = new ArrayList<Integer>();
	private final int laplacianSmoothing;
	private int total;

	public CalcProbability(int k) {
		super();
		this.laplacianSmoothing = k;
	}
	
	public CalcProbability() {
		this(0);
	}
	
	public void addClass(int items) {
		total+=items;
		this.classes.add(items);
	}
	
	public int getClassCount() {
		return this.classes.size();
	}
	
	public double calculate(int classNumber) {
		double classItems = this.classes.get(classNumber);
		double totalItems = this.total;
		double d = ((double)this.laplacianSmoothing*(double)classes.size());
		return (classItems + ((double)this.laplacianSmoothing)) / (totalItems+d);
	}
}