/*
* Copyright (C) 2011 Clearspring Technologies, Inc.
*
* Licensed 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 com.clearspring.analytics.stream;
import java.util.List;
import java.util.Random;
import org.junit.Before;
import org.junit.Test;
import cern.jet.random.Distributions;
import cern.jet.random.engine.RandomEngine;
import static org.junit.Assert.assertTrue;
public class TestStochasticTopper {
private static final int NUM_ITERATIONS = 100000;
private static final int NUM_ELEMENTS = 10;
private StochasticTopper<Integer> vs;
private Random random;
@Before
public void setUp() {
vs = new StochasticTopper<Integer>(200);
random = new Random(340340990L);
}
@Test
public void testGaussianDistribution() {
for (int i = 0; i < NUM_ITERATIONS; i++) {
vs.offer(new Integer((int) Math.round((random.nextGaussian() * NUM_ELEMENTS))));
}
List<Integer> top = vs.peek(5);
System.out.println("Gaussian:");
for (Integer e : top) {
System.out.println(e);
}
int tippyTop = top.get(0);
assertTrue(tippyTop > -15 && tippyTop < 15);
}
@Test
public void testZipfianDistribution() {
RandomEngine re = RandomEngine.makeDefault();
for (int i = 0; i < NUM_ITERATIONS; i++) {
int z = Distributions.nextZipfInt(1.2D, re);
vs.offer(z);
}
List<Integer> top = vs.peek(5);
System.out.println("Zipfian:");
for (Integer e : top) {
System.out.println(e);
}
int tippyTop = top.get(0);
assertTrue(tippyTop < 3);
}
@Test
public void testGeometricDistribution() {
RandomEngine re = RandomEngine.makeDefault();
for (int i = 0; i < NUM_ITERATIONS; i++) {
int z = Distributions.nextGeometric(0.25, re);
vs.offer(z);
}
List<Integer> top = vs.peek(5);
System.out.println("Geometric:");
for (Integer e : top) {
System.out.println(e);
}
int tippyTop = top.get(0);
assertTrue(tippyTop < 3);
}
@Test
public void testRandomEngine() {
int[] maxcounts = new int[10];
int[] counts = new int[20];
RandomEngine re = RandomEngine.makeDefault();
for (int i = 0; i < NUM_ITERATIONS; i++) {
// int z = Distributions.nextZipfInt(1.2D, re);
int z = Distributions.nextGeometric(0.25, re);
if (z > Integer.MAX_VALUE - 9) {
maxcounts[Integer.MAX_VALUE - z]++;
}
if (z < 20) {
counts[z]++;
}
}
for (int i = 0; i < 20; i++) {
System.out.println(i + ": " + counts[i]);
}
for (int i = 9; i >= 0; i--) {
System.out.println((Integer.MAX_VALUE - i) + ": " + maxcounts[i]);
}
}
}