| /* |
| * Copyright (C) 2019, Matthias Sohn <matthias.sohn@sap.com> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.jgit.util; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.assertTrue; |
| |
| import org.eclipse.jgit.util.Stats; |
| import org.junit.Test; |
| |
| public class StatsTest { |
| @Test |
| public void testStatsTrivial() { |
| Stats s = new Stats(); |
| s.add(1); |
| s.add(1); |
| s.add(1); |
| assertEquals(3, s.count()); |
| assertEquals(1.0, s.min(), 1E-6); |
| assertEquals(1.0, s.max(), 1E-6); |
| assertEquals(1.0, s.avg(), 1E-6); |
| assertEquals(0.0, s.var(), 1E-6); |
| assertEquals(0.0, s.stddev(), 1E-6); |
| } |
| |
| @Test |
| public void testStats() { |
| Stats s = new Stats(); |
| s.add(1); |
| s.add(2); |
| s.add(3); |
| s.add(4); |
| assertEquals(4, s.count()); |
| assertEquals(1.0, s.min(), 1E-6); |
| assertEquals(4.0, s.max(), 1E-6); |
| assertEquals(2.5, s.avg(), 1E-6); |
| assertEquals(1.666667, s.var(), 1E-6); |
| assertEquals(1.290994, s.stddev(), 1E-6); |
| } |
| |
| @Test |
| /** |
| * see |
| * https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Example |
| */ |
| public void testStatsCancellationExample1() { |
| Stats s = new Stats(); |
| s.add(1E8 + 4); |
| s.add(1E8 + 7); |
| s.add(1E8 + 13); |
| s.add(1E8 + 16); |
| assertEquals(4, s.count()); |
| assertEquals(1E8 + 4, s.min(), 1E-6); |
| assertEquals(1E8 + 16, s.max(), 1E-6); |
| assertEquals(1E8 + 10, s.avg(), 1E-6); |
| assertEquals(30, s.var(), 1E-6); |
| assertEquals(5.477226, s.stddev(), 1E-6); |
| } |
| |
| @Test |
| /** |
| * see |
| * https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Example |
| */ |
| public void testStatsCancellationExample2() { |
| Stats s = new Stats(); |
| s.add(1E9 + 4); |
| s.add(1E9 + 7); |
| s.add(1E9 + 13); |
| s.add(1E9 + 16); |
| assertEquals(4, s.count()); |
| assertEquals(1E9 + 4, s.min(), 1E-6); |
| assertEquals(1E9 + 16, s.max(), 1E-6); |
| assertEquals(1E9 + 10, s.avg(), 1E-6); |
| assertEquals(30, s.var(), 1E-6); |
| assertEquals(5.477226, s.stddev(), 1E-6); |
| } |
| |
| @Test |
| public void testNoValues() { |
| Stats s = new Stats(); |
| assertTrue(Double.isNaN(s.var())); |
| assertTrue(Double.isNaN(s.stddev())); |
| assertTrue(Double.isNaN(s.avg())); |
| assertTrue(Double.isNaN(s.min())); |
| assertTrue(Double.isNaN(s.max())); |
| s.add(42.3); |
| assertTrue(Double.isNaN(s.var())); |
| assertTrue(Double.isNaN(s.stddev())); |
| assertEquals(42.3, s.avg(), 1E-6); |
| assertEquals(42.3, s.max(), 1E-6); |
| assertEquals(42.3, s.min(), 1E-6); |
| s.add(42.3); |
| assertEquals(0, s.var(), 1E-6); |
| assertEquals(0, s.stddev(), 1E-6); |
| } |
| } |