001 /* 002 * Copyright (C) 2008-2010 by Holger Arndt 003 * 004 * This file is part of the Universal Java Matrix Package (UJMP). 005 * See the NOTICE file distributed with this work for additional 006 * information regarding copyright ownership and licensing. 007 * 008 * UJMP is free software; you can redistribute it and/or modify 009 * it under the terms of the GNU Lesser General Public License as 010 * published by the Free Software Foundation; either version 2 011 * of the License, or (at your option) any later version. 012 * 013 * UJMP is distributed in the hope that it will be useful, 014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 016 * GNU Lesser General Public License for more details. 017 * 018 * You should have received a copy of the GNU Lesser General Public 019 * License along with UJMP; if not, write to the 020 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, 021 * Boston, MA 02110-1301 USA 022 */ 023 024 package org.ujmp.core.objectmatrix.calculation; 025 026 import java.util.ArrayList; 027 import java.util.List; 028 029 import org.ujmp.core.Matrix; 030 import org.ujmp.core.exceptions.MatrixException; 031 import org.ujmp.core.util.MathUtil; 032 033 public class Bootstrap extends AbstractObjectCalculation { 034 private static final long serialVersionUID = -5084329826465538416L; 035 036 private int count = 0; 037 038 private Matrix selection = null; 039 040 public Bootstrap(Matrix m) { 041 this(m, (int) m.getRowCount()); 042 } 043 044 public Bootstrap(Matrix m, int count) { 045 super(m); 046 this.count = count; 047 } 048 049 public Object getObject(long... coordinates) throws MatrixException { 050 if (selection == null) { 051 List<Integer> rows = new ArrayList<Integer>(); 052 for (int i = 0; i < count; i++) { 053 int s = MathUtil.nextInteger(0, (int) getSource().getRowCount() - 1); 054 rows.add(s); 055 } 056 selection = getSource().selectRows(Ret.LINK, rows); 057 } 058 return selection.getAsObject(coordinates); 059 } 060 061 @Override 062 public long[] getSize() { 063 return new long[] { count, getSource().getColumnCount() }; 064 } 065 066 }