Here you can find the source of norm(double[] array)
public static double norm(double[] array)
//package com.java2s; /**/*from w w w . jav a 2s. c o m*/ * This file is part of the Java Machine Learning Library * * The Java Machine Learning Library is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * The Java Machine Learning Library 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with the Java Machine Learning Library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Copyright (c) 2006-2009, Thomas Abeel * * Project: http://java-ml.sourceforge.net/ * */ public class Main { /** * Returns the norm of the vector * * @return the norm of the vector */ public static double norm(double[] array) { if (array != null) { int n = array.length; double sum = 0.0; for (int i = 0; i < n; i++) { sum += array[i] * array[i]; } return Math.pow(sum, 0.5); } else return 0.0; } }