/*
* 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 SpreadSubsample. Run from the command line with:<p>
* java weka.filters.supervised.instance.SpreadSubsampleTest
*
* @author <a href="mailto:len@reeltwo.com">Len Trigg</a>
* @version $Revision: 1.3 $
*/
public class SpreadSubsampleTest extends AbstractFilterTest {
private static double TOLERANCE = 0.001;
public SpreadSubsampleTest(String name) { super(name); }
/** Creates a default SpreadSubsample */
public Filter getFilter() {
SpreadSubsample f = new SpreadSubsample();
f.setDistributionSpread(0);
return f;
}
/** Remove string attributes from default fixture instances */
protected void setUp() throws Exception {
super.setUp();
m_Instances.setClassIndex(1);
}
public void testDistributionSpread() throws Exception {
testDistributionSpread_X(1.0);
testDistributionSpread_X(2.0);
testDistributionSpread_X(3.0);
}
public void testAdjustWeights() {
((SpreadSubsample)m_Filter).setAdjustWeights(true);
Instances result = useFilter();
assertEquals(m_Instances.numAttributes(), result.numAttributes());
double origWeight = 0;
for (int i = 0; i < m_Instances.numInstances(); i++) {
origWeight += m_Instances.instance(i).weight();
}
double outWeight = 0;
for (int i = 0; i < result.numInstances(); i++) {
outWeight += result.instance(i).weight();
}
assertEquals(origWeight, outWeight, TOLERANCE);
}
private void testDistributionSpread_X(double factor) throws Exception {
AttributeStats origs = m_Instances.attributeStats(1);
assertNotNull(origs.nominalCounts);
((SpreadSubsample)m_Filter).setDistributionSpread(factor);
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 min = outs.nominalCounts[0];
int max = outs.nominalCounts[0];
for (int i = 1; i < outs.nominalCounts.length; i++) {
if (outs.nominalCounts[i] < min) {
min = outs.nominalCounts[i];
}
if (outs.nominalCounts[i] > max) {
max = outs.nominalCounts[i];
}
}
assertTrue(max / factor <= min);
}
public static Test suite() {
return new TestSuite(SpreadSubsampleTest.class);
}
public static void main(String[] args){
junit.textui.TestRunner.run(suite());
}
}