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.align.util;
022
023import java.util.Collection;
024import java.util.Iterator;
025
026/**
027 * Utilities for working with collections.
028 *
029 * @author Thomas Down
030 */
031public class CollectionTools {
032        public static int[] toIntArray(Collection<Number> l) {
033                int[] a = new int[l.size()];
034                int i = 0;
035                for (Iterator<Number> j = l.iterator(); j.hasNext(); ) {
036                        a[i++] = ( j.next()).intValue();
037                }
038                return a;
039        }
040
041        public static double[] toDoubleArray(Collection<Number> l) {
042                double[] a = new double[l.size()];
043                int i = 0;
044                for (Iterator<Number> j = l.iterator(); j.hasNext(); ) {
045                        a[i++] = j.next().doubleValue();
046                }
047                return a;
048        }
049
050        public static Object randomPick(Collection<Number> col) {
051                Object[] objs = col.toArray(new Object[col.size()]);
052                return objs[(int) Math.floor(Math.random() * objs.length)];
053        }
054}