/*
 * 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 junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

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

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

/**
 * Certified data test cases.
 * 
 * @version $Revision$ $Date$
 */
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);
	}

	/**
	 * @return The test suite
	 */
	public static Test suite() {
		TestSuite suite = new TestSuite(CertifiedDataTest.class);
		suite.setName("Certified Tests");
		return suite;
	}

	/**
	 * 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();
	}
}
