TestStats.java

/**
 * Copyright (c) 2013 Oculus Info Inc.
 * http://www.oculusinfo.com/
 *
 * Released under the MIT License.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package spimedb.util.math.statistics;

import junit.framework.Assert;
import org.junit.Test;

public class TestStats {
    private static final double EPSILON = 1E-12;

    @Test
    public void testMean () {
        StatTracker s = new StatTracker();
        s.addStat(0.0);
        s.addStat(1.0);
        s.addStat(2.0);
        Assert.assertEquals(1.0, s.mean(), EPSILON);
        s.addStat(3.0);
        Assert.assertEquals(1.5, s.mean(), EPSILON);
    }

    @Test
    public void testVariance () {
        StatTracker s = new StatTracker();
        s.addStat(0.0);
        s.addStat(1.0);
        s.addStat(2.0);
        Assert.assertEquals(2.0/3.0, s.variance(), EPSILON);

        s.addStat(3.0);
        Assert.assertEquals(5.0/4.0, s.variance(), EPSILON);
    }

    @Test
    public void testReset () {
        StatTracker s = new StatTracker();
        s.addStat(0.0);
        s.addStat(1.0);
        s.addStat(2.0);
        s.addStat(3.0);
        Assert.assertEquals(1.5, s.mean(), EPSILON);

        s.reset();
        s.addStat(0.0);
        s.addStat(1.0);
        Assert.assertEquals(0.5, s.mean(), EPSILON);
    }
}