| /* |
| * 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.pig.test; |
| |
| |
| import static org.junit.Assert.assertTrue; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Random; |
| |
| import org.apache.pig.data.BagFactory; |
| import org.apache.pig.data.DataBag; |
| import org.apache.pig.data.InternalMap; |
| import org.apache.pig.data.NonSpillableDataBag; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.TupleFactory; |
| import org.apache.pig.impl.builtin.FindQuantiles; |
| import org.junit.Test; |
| |
| public class TestFindQuantiles { |
| |
| private static TupleFactory tFact = TupleFactory.getInstance(); |
| private static final float epsilon = 0.0001f; |
| |
| @Test |
| public void testFindQuantiles() throws Exception { |
| final int numSamples = 97778; |
| final int numReducers = 1009; |
| float sum = getProbVecSum(numSamples, numReducers); |
| System.out.println("sum: " + sum); |
| assertTrue(sum > (1-epsilon) && sum < (1+epsilon)); |
| } |
| |
| @Test |
| public void testFindQuantiles2() throws Exception { |
| final int numSamples = 30000; |
| final int numReducers = 3000; |
| float sum = getProbVecSum(numSamples, numReducers); |
| System.out.println("sum: " + sum); |
| assertTrue(sum > (1-epsilon) && sum < (1+epsilon)); |
| } |
| |
| @Test |
| public void testFindQuantilesRemainder() throws Exception { |
| final int numSamples = 1900; |
| final int numReducers = 300; |
| DataBag samples = generateRandomSortedSamples(numSamples, 365); |
| Map<String, Object> findQuantilesResult = getFindQuantilesResult(samples, numReducers); |
| DataBag quantilesBag = (DataBag)findQuantilesResult.get(FindQuantiles.QUANTILES_LIST); |
| Iterator<Tuple> iter = quantilesBag.iterator(); |
| Tuple lastQuantile = null; |
| while (iter.hasNext()) { |
| lastQuantile = iter.next(); |
| } |
| int lastQuantileNum = (Integer)lastQuantile.get(0); |
| int count = 0; |
| iter = samples.iterator(); |
| while (iter.hasNext()) { |
| Tuple t = iter.next(); |
| int num = (Integer)t.get(0); |
| if (num >= lastQuantileNum) { |
| count++; |
| } |
| } |
| assertTrue((double)count/numSamples <= 1.0/365 + 0.001); |
| } |
| |
| private float[] getProbVec(Tuple values) throws Exception { |
| float[] probVec = new float[values.size()]; |
| for(int i = 0; i < values.size(); i++) { |
| probVec[i] = (Float)values.get(i); |
| } |
| return probVec; |
| } |
| |
| private DataBag generateRandomSortedSamples(int numSamples, int max) throws Exception { |
| Random rand = new Random(1000); |
| List<Tuple> samples = new ArrayList<Tuple>(); |
| for (int i=0; i<numSamples; i++) { |
| Tuple t = tFact.newTuple(1); |
| t.set(0, rand.nextInt(max)); |
| samples.add(t); |
| } |
| Collections.sort(samples); |
| return new NonSpillableDataBag(samples); |
| } |
| |
| private DataBag generateUniqueSamples(int numSamples) throws Exception { |
| DataBag samples = BagFactory.getInstance().newDefaultBag(); |
| for (int i=0; i<numSamples; i++) { |
| Tuple t = tFact.newTuple(1); |
| t.set(0, new Integer(23)); |
| samples.add(t); |
| } |
| return samples; |
| } |
| |
| private Map<String, Object> getFindQuantilesResult(DataBag samples, |
| int numReduceres) throws Exception { |
| Tuple in = tFact.newTuple(2); |
| |
| in.set(0, new Integer(numReduceres)); |
| in.set(1, samples); |
| |
| FindQuantiles fq = new FindQuantiles(); |
| |
| Map<String, Object> res = fq.exec(in); |
| return res; |
| } |
| |
| private float getProbVecSum(int numSamples, int numReduceres) throws Exception { |
| DataBag samples = generateUniqueSamples(numSamples); |
| Map<String, Object> res = getFindQuantilesResult(samples, numReduceres); |
| |
| InternalMap weightedPartsData = (InternalMap) res.get(FindQuantiles.WEIGHTED_PARTS); |
| Iterator<Object> it = weightedPartsData.values().iterator(); |
| float[] probVec = getProbVec((Tuple)it.next()); |
| float sum = 0.0f; |
| for (float f : probVec) { |
| sum += f; |
| } |
| return sum; |
| } |
| |
| } |