Here you can find the source of collapse(double[] w)
public static double collapse(double[] w)
//package com.java2s; /*//w w w .j a v a 2s . c o m * #%L * G * %% * Copyright (C) 2014 Giovanni Stilo * %% * G is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program. If not, see * <https://www.gnu.org/licenses/lgpl-3.0.txt>. * #L% */ public class Main { public static double collapse(double[] w) { if (w == null) { return 0.0; } double summ = 0.0d; for (int i = 0; i < w.length; i++) { summ += w[i]; } return summ; } }