/*
 * DSI utilities
 *
 * Copyright (C) 2011-2020 Sebastiano Vigna
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License as published by the Free
 *  Software Foundation; either version 3 of the License, or (at your option)
 *  any later version.
 *
 *  This library 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 Lesser General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

package it.unimi.dsi.stat;

import static org.junit.Assert.assertEquals;

import java.util.ArrayList;

import org.junit.Test;


public class JackknifeTest {
	@Test
	public void test() {
		final ArrayList<double[]> samples = new ArrayList<>();
		samples.add(new double[] { 1 });
		samples.add(new double[] { 2 });
		samples.add(new double[] { 3 });
		// Linear statistics must pass through the jackknife without bias.
		final Jackknife average = Jackknife.compute(samples, Jackknife.IDENTITY);
		assertEquals(2, average.estimate[0], 1E-30);
		assertEquals(Math.sqrt(((1 - 2) * (1 - 2) + (3 - 2) * (3 - 2)) / 6.), average.standardError[0], 1E-30);
	}
}
