001/*
002 *                    BioJava development code
003 *
004 * This code may be freely distributed and modified under the
005 * terms of the GNU Lesser General Public Licence.  This should
006 * be distributed with the code.  If you do not have a copy,
007 * see:
008 *
009 *      http://www.gnu.org/copyleft/lesser.html
010 *
011 * Copyright for this code is held jointly by the individual
012 * authors.  These should be listed in @author doc comments.
013 *
014 * For more information on the BioJava project and its aims,
015 * or to join the biojava-l mailing list, visit the home page
016 * at:
017 *
018 *      http://www.biojava.org/
019 *
020 */
021package org.biojava.nbio.structure.jama;
022
023public class Maths {
024
025        /** sqrt(a^2 + b^2) without under/overflow.
026         * @param a a double
027         * @param b a double
028         * @return a double
029         * */
030
031        public static double hypot(double a, double b) {
032                double r;
033                if (Math.abs(a) > Math.abs(b)) {
034                        r = b/a;
035                        r = Math.abs(a)*Math.sqrt(1+r*r);
036                } else if (b != 0) {
037                        r = a/b;
038                        r = Math.abs(b)*Math.sqrt(1+r*r);
039                } else {
040                        r = 0.0;
041                }
042                return r;
043        }
044}