/**
 * Copyright (C) 2001-2017 by RapidMiner and the contributors
 * 
 * Complete list of developers available at our web site:
 * 
 * http://rapidminer.com
 * 
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU Affero General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program 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
 * Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License along with this program.
 * If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.tools.math.function.aggregation;

import com.rapidminer.example.Attribute;


/**
 * This aggregation function calculates the product of all given values.
 * 
 * @author Sebastian Land
 * 
 */
public class ProductFunction extends AbstractAggregationFunction {

	private double product = 1d;

	public ProductFunction() {}

	public ProductFunction(Boolean ignoreMissings) {
		super(ignoreMissings);
	}

	@Override
	protected void reset() {
		this.product = 1d;
	}

	@Override
	public String getName() {
		return "product";
	}

	@Override
	public double getValue() {
		return product;
	}

	@Override
	public boolean supportsAttribute(Attribute attribute) {
		return attribute.isNumerical();
	}

	@Override
	public void update(double value, double weight) {
		if (!Double.isNaN(value) && !Double.isNaN(weight)) {
			product *= (value * weight);
		}
	}

	@Override
	public void update(double value) {
		if (!Double.isNaN(value)) {
			product *= value;
		}
	}
}