/*
* This program 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.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Copyright (C) 2002 University of Waikato
*/
package weka.filters.supervised.instance;
import weka.core.AttributeStats;
import weka.core.Instances;
import weka.filters.AbstractFilterTest;
import weka.filters.Filter;
import junit.framework.Test;
import junit.framework.TestSuite;
/**
* Tests Resample. Run from the command line with:<p>
* java weka.filters.supervised.instance.ResampleTest
*
* @author <a href="mailto:len@reeltwo.com">Len Trigg</a>
* @version $Revision: 1.3 $
*/
public class ResampleTest
extends AbstractFilterTest {
public ResampleTest(String name) { super(name); }
/** Need to set the class index */
protected void setUp() throws Exception {
super.setUp();
m_Instances.setClassIndex(1);
}
/** Creates a default Resample */
public Filter getFilter() {
Resample f = new Resample();
f.setSampleSizePercent(50);
return f;
}
public void testSampleSizePercent() {
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
assertEquals("Expecting output to be 50% of input",
m_Instances.numInstances() / 2, result.numInstances());
((Resample)m_Filter).setSampleSizePercent(200);
result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
assertEquals("Expecting output to be 200% of input",
m_Instances.numInstances() * 2, result.numInstances());
}
public void testSampleSizePercentNoReplacement() {
((Resample) m_Filter).setSampleSizePercent(20);
((Resample) m_Filter).setNoReplacement(true);
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
assertEquals("Expecting output to be 20% of input",
(int) (m_Instances.numInstances() * 20.0 / 100), result.numInstances());
}
public void testSampleSizePercentNoReplacementInverted() {
((Resample) m_Filter).setSampleSizePercent(20);
((Resample) m_Filter).setNoReplacement(true);
((Resample) m_Filter).setInvertSelection(true);
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
assertEquals("Expecting output to be 80% of input (20% inverted)",
m_Instances.numInstances()
- (int) (m_Instances.numInstances() * 20.0 / 100), result.numInstances());
}
public void testNoBias() throws Exception {
m_Instances.setClassIndex(1);
AttributeStats origs = m_Instances.attributeStats(1);
assertNotNull(origs.nominalCounts);
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
AttributeStats outs = result.attributeStats(1);
// Check distributions are pretty similar
assertNotNull(outs.nominalCounts);
assertEquals(origs.nominalCounts.length, outs.nominalCounts.length);
for (int i = 0; i < origs.nominalCounts.length; i++) {
int est = origs.nominalCounts[i] / 2 - 1;
assertTrue("Counts for value:" + i
+ " orig:" + origs.nominalCounts[i]
+ " out50%:" + outs.nominalCounts[i],
(est <= outs.nominalCounts[i]) &&
(outs.nominalCounts[i] <= (est + 3)));
}
}
public void testBiasToUniform() throws Exception {
m_Instances.setClassIndex(1);
AttributeStats origs = m_Instances.attributeStats(1);
assertNotNull(origs.nominalCounts);
((Resample)m_Filter).setBiasToUniformClass(1.0);
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
AttributeStats outs = result.attributeStats(1);
// Check distributions are pretty similar
assertNotNull(outs.nominalCounts);
assertEquals(origs.nominalCounts.length, outs.nominalCounts.length);
int est = (origs.totalCount - origs.missingCount) / origs.distinctCount;
est = est / 2 - 1;
for (int i = 0; i < origs.nominalCounts.length; i++) {
assertTrue("Counts for value:" + i
+ " orig:" + origs.nominalCounts[i]
+ " out50%:" + outs.nominalCounts[i]
+ " ~wanted:" + est,
(est <= outs.nominalCounts[i]) &&
(outs.nominalCounts[i] <= (est + 3)));
}
}
public static Test suite() {
return new TestSuite(ResampleTest.class);
}
public static void main(String[] args){
junit.textui.TestRunner.run(suite());
}
}