Commons Math example source code file (CertifiedDataTest.java)

This example Commons Math source code file (CertifiedDataTest.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

bufferedreader, certifieddatatest, descriptivestatistics, descriptivestatistics, exception, io, mavro, mavro, michelso, michelso, numacc1, numacc2, pidigits, pidigits, summarystatistics

The Commons Math CertifiedDataTest.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.stat;

import java.io.BufferedReader;
import java.io.InputStreamReader;

import junit.framework.TestCase;

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

/**
 * Certified data test cases.
 * @version $Revision: 902201 $ $Date: 2010-01-22 13:18:16 -0500 (Fri, 22 Jan 2010) $
 */
public class CertifiedDataTest extends TestCase  {

    protected double mean = Double.NaN;

    protected double std = Double.NaN;

    /**
     * Certified Data Test Constructor
     * @param name
     */
    public CertifiedDataTest(String name) {
        super(name);
    }

    /**
     * Test SummaryStatistics - implementations that do not store the data
     * and use single pass algorithms to compute statistics
    */
    public void testSummaryStatistics() throws Exception {
        SummaryStatistics u = new SummaryStatistics();
        loadStats("data/PiDigits.txt", u);
        assertEquals("PiDigits: std", std, u.getStandardDeviation(), 1E-13);
        assertEquals("PiDigits: mean", mean, u.getMean(), 1E-13);

        loadStats("data/Mavro.txt", u);
        assertEquals("Mavro: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("Mavro: mean", mean, u.getMean(), 1E-14);

        loadStats("data/Michelso.txt", u);
        assertEquals("Michelso: std", std, u.getStandardDeviation(), 1E-13);
        assertEquals("Michelso: mean", mean, u.getMean(), 1E-13);

        loadStats("data/NumAcc1.txt", u);
        assertEquals("NumAcc1: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("NumAcc1: mean", mean, u.getMean(), 1E-14);

        loadStats("data/NumAcc2.txt", u);
        assertEquals("NumAcc2: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("NumAcc2: mean", mean, u.getMean(), 1E-14);
    }

    /**
     * Test DescriptiveStatistics - implementations that store full array of
     * values and execute multi-pass algorithms
     */
    public void testDescriptiveStatistics() throws Exception {

        DescriptiveStatistics u = new DescriptiveStatistics();

        loadStats("data/PiDigits.txt", u);
        assertEquals("PiDigits: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("PiDigits: mean", mean, u.getMean(), 1E-14);

        loadStats("data/Mavro.txt", u);
        assertEquals("Mavro: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("Mavro: mean", mean, u.getMean(), 1E-14);

        loadStats("data/Michelso.txt", u);
        assertEquals("Michelso: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("Michelso: mean", mean, u.getMean(), 1E-14);

        loadStats("data/NumAcc1.txt", u);
        assertEquals("NumAcc1: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("NumAcc1: mean", mean, u.getMean(), 1E-14);

        loadStats("data/NumAcc2.txt", u);
        assertEquals("NumAcc2: std", std, u.getStandardDeviation(), 1E-14);
        assertEquals("NumAcc2: mean", mean, u.getMean(), 1E-14);
    }

    /**
     * loads a DescriptiveStatistics off of a test file
     * @param file
     * @param statistical summary
     */
    private void loadStats(String resource, Object u) throws Exception {

        DescriptiveStatistics d = null;
        SummaryStatistics s = null;
        if (u instanceof DescriptiveStatistics) {
            d = (DescriptiveStatistics) u;
        } else {
            s = (SummaryStatistics) u;
        }
        u.getClass().getDeclaredMethod(
                "clear", new Class[]{}).invoke(u, new Object[]{});
        mean = Double.NaN;
        std = Double.NaN;

        BufferedReader in =
            new BufferedReader(
                    new InputStreamReader(
                            CertifiedDataTest.class.getResourceAsStream(resource)));

        String line = null;

        for (int j = 0; j < 60; j++) {
            line = in.readLine();
            if (j == 40) {
                mean =
                    Double.parseDouble(
                            line.substring(line.lastIndexOf(":") + 1).trim());
            }
            if (j == 41) {
                std =
                    Double.parseDouble(
                            line.substring(line.lastIndexOf(":") + 1).trim());
            }
        }

        line = in.readLine();

        while (line != null) {
            if (d != null) {
                d.addValue(Double.parseDouble(line.trim()));
            }  else {
                s.addValue(Double.parseDouble(line.trim()));
            }
            line = in.readLine();
        }

        in.close();
    }
}