/**
 * Copyright 2010 Neuroph Project http://neuroph.sourceforge.net
 *
 * 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.neuroph.core.input;

import java.io.Serializable;
import java.util.List;
import org.neuroph.core.Connection;

/**
 * Performs multiplication of all input vector elements.
 *
 * @author Zoran Sevarac 
 */
public class Product extends InputFunction implements Serializable {

    /**
     * The class fingerprint that is set to indicate serialization compatibility
     * with a previous version of the class.
     */
    private static final long serialVersionUID = 2L;

    @Override
    public double getOutput(List inputConnections) {
        if (inputConnections.size() == 0) {
            return 0d;
        }

        double output = 1d;

        for (Connection connection : inputConnections) {
            output *= connection.getInput();
        }

        return output;
    }
}