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Commons Math example source code file (ValueServerTest.java)

This example Commons Math source code file (ValueServerTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Math tags/keywords

eofexception, exception, exception, expecting, illegalstateexception, illegalstateexception, io, net, network, override, retrytestcase, summarystatistics, summarystatistics, url, url, valueserver, valueservertest

The Commons Math ValueServerTest.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.math.random;

import java.io.EOFException;
import java.net.URL;

import org.apache.commons.math.RetryTestCase;
import org.apache.commons.math.stat.descriptive.SummaryStatistics;

/**
 * Test cases for the ValueServer class.
 *
 * @version $Revision: 902201 $ $Date: 2010-01-22 13:18:16 -0500 (Fri, 22 Jan 2010) $
 */

public final class ValueServerTest extends RetryTestCase {

    private ValueServer vs = new ValueServer();

    public ValueServerTest(String name) {
        super(name);
    }

    @Override
    public void setUp() {
        vs.setMode(ValueServer.DIGEST_MODE);
        try {
            URL url = getClass().getResource("testData.txt");
            vs.setValuesFileURL(url);
        } catch (Exception ex) {
            fail("malformed test URL");
        }
    }

    /**
      * Generate 1000 random values and make sure they look OK.<br>
      * Note that there is a non-zero (but very small) probability that
      * these tests will fail even if the code is working as designed.
      */
    public void testNextDigest() throws Exception{
        double next = 0.0;
        double tolerance = 0.1;
        vs.computeDistribution();
        assertTrue("empirical distribution property",
            vs.getEmpiricalDistribution() != null);
        SummaryStatistics stats = new SummaryStatistics();
        for (int i = 1; i < 1000; i++) {
            next = vs.getNext();
            stats.addValue(next);
        }
        assertEquals("mean", 5.069831575018909, stats.getMean(), tolerance);
        assertEquals
         ("std dev", 1.0173699343977738, stats.getStandardDeviation(),
            tolerance);

        vs.computeDistribution(500);
        stats = new SummaryStatistics();
        for (int i = 1; i < 1000; i++) {
            next = vs.getNext();
            stats.addValue(next);
        }
        assertEquals("mean", 5.069831575018909, stats.getMean(), tolerance);
        assertEquals
         ("std dev", 1.0173699343977738, stats.getStandardDeviation(),
            tolerance);

    }

    /**
      * Make sure exception thrown if digest getNext is attempted
      * before loading empiricalDistribution.
      */
    public void testNextDigestFail() throws Exception {
        try {
            vs.getNext();
            fail("Expecting IllegalStateException");
        } catch (IllegalStateException ex) {}
    }

    public void testEmptyReplayFile() {
        try {
            URL url = getClass().getResource("emptyFile.txt");
            vs.setMode(ValueServer.REPLAY_MODE);
            vs.setValuesFileURL(url);
            vs.getNext();
            fail("an exception should have been thrown");
        } catch (EOFException eof) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }
    }

    public void testEmptyDigestFile() {
        try {
            URL url = getClass().getResource("emptyFile.txt");
            vs.setMode(ValueServer.DIGEST_MODE);
            vs.setValuesFileURL(url);
            vs.computeDistribution();
            fail("an exception should have been thrown");
        } catch (EOFException eof) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }
    }

    /**
     * Test ValueServer REPLAY_MODE using values in testData file.<br>
     * Check that the values 1,2,1001,1002 match data file values 1 and 2.
     * the sample data file.
     */
    public void testReplay() throws Exception {
        double firstDataValue = 4.038625496201205;
        double secondDataValue = 3.6485326248346936;
        double tolerance = 10E-15;
        double compareValue = 0.0d;
        vs.setMode(ValueServer.REPLAY_MODE);
        vs.resetReplayFile();
        compareValue = vs.getNext();
        assertEquals(compareValue,firstDataValue,tolerance);
        compareValue = vs.getNext();
        assertEquals(compareValue,secondDataValue,tolerance);
        for (int i = 3; i < 1001; i++) {
           compareValue = vs.getNext();
        }
        compareValue = vs.getNext();
        assertEquals(compareValue,firstDataValue,tolerance);
        compareValue = vs.getNext();
        assertEquals(compareValue,secondDataValue,tolerance);
        vs.closeReplayFile();
        // make sure no NPE
        vs.closeReplayFile();
    }

    /**
     * Test other ValueServer modes
     */
    public void testModes() throws Exception {
        vs.setMode(ValueServer.CONSTANT_MODE);
        vs.setMu(0);
        assertEquals("constant mode test",vs.getMu(),vs.getNext(),Double.MIN_VALUE);
        vs.setMode(ValueServer.UNIFORM_MODE);
        vs.setMu(2);
        double val = vs.getNext();
        assertTrue(val > 0 && val < 4);
        vs.setSigma(1);
        vs.setMode(ValueServer.GAUSSIAN_MODE);
        val = vs.getNext();
        assertTrue("gaussian value close enough to mean",
            val < vs.getMu() + 100*vs.getSigma());
        vs.setMode(ValueServer.EXPONENTIAL_MODE);
        val = vs.getNext();
        assertTrue(val > 0);
        try {
            vs.setMode(1000);
            vs.getNext();
            fail("bad mode, expecting IllegalStateException");
        } catch (IllegalStateException ex) {
            // ignored
        }
    }

    /**
     * Test fill
     */
    public void testFill() throws Exception {
        vs.setMode(ValueServer.CONSTANT_MODE);
        vs.setMu(2);
        double[] val = new double[5];
        vs.fill(val);
        for (int i = 0; i < 5; i++) {
            assertEquals("fill test in place",2,val[i],Double.MIN_VALUE);
        }
        double v2[] = vs.fill(3);
        for (int i = 0; i < 3; i++) {
            assertEquals("fill test in place",2,v2[i],Double.MIN_VALUE);
        }
    }

    /**
     * Test getters to make Clover happy
     */
    public void testProperties() throws Exception {
        vs.setMode(ValueServer.CONSTANT_MODE);
        assertEquals("mode test",ValueServer.CONSTANT_MODE,vs.getMode());
        vs.setValuesFileURL("http://www.apache.org");
        URL url = vs.getValuesFileURL();
        assertEquals("valuesFileURL test","http://www.apache.org",url.toString());
    }

}

Other Commons Math examples (source code examples)

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