Added: mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/common/TopKMinKTest.java URL: http://svn.apache.org/viewvc/mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/common/TopKMinKTest.java?rev=1130443&view=auto ============================================================================== --- mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/common/TopKMinKTest.java (added) +++ mahout/trunk/core/src/test/java/org/apache/mahout/cf/taste/common/TopKMinKTest.java Thu Jun 2 09:07:49 2011 @@ -0,0 +1,116 @@ +/** + * 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.mahout.cf.taste.common; + +import org.junit.Test; + +import java.util.Comparator; +import java.util.List; + +import static org.junit.Assert.assertEquals; + +/** + * tests for {@link TopK} and {@link MinK} + */ +public class TopKMinKTest { + + static class IntComparator implements Comparator<Integer> { + @Override + public int compare(Integer one, Integer two) { + return one.compareTo(two); + } + } + + @Test + public void oneMillionTop() { + TopK<Integer> topFiveNumbers = new TopK<Integer>(5, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + topFiveNumbers.offer(n); + } + + List<Integer> numbers = topFiveNumbers.retrieve(); + assertEquals(new Integer(1000000), numbers.get(0)); + assertEquals(new Integer(999999), numbers.get(1)); + assertEquals(new Integer(999998), numbers.get(2)); + assertEquals(new Integer(999997), numbers.get(3)); + assertEquals(new Integer(999996), numbers.get(4)); + } + + @Test + public void oneMillionSmallestTop() { + TopK<Integer> topFiveNumbers = new TopK<Integer>(5, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + topFiveNumbers.offer(n); + } + + assertEquals(new Integer(999996), topFiveNumbers.smallestGreat()); + } + + @Test + public void oneMillionMin() { + MinK<Integer> minFiveNumbers = new MinK<Integer>(5, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + minFiveNumbers.offer(n); + } + + List<Integer> numbers = minFiveNumbers.retrieve(); + assertEquals(new Integer(1), numbers.get(0)); + assertEquals(new Integer(2), numbers.get(1)); + assertEquals(new Integer(3), numbers.get(2)); + assertEquals(new Integer(4), numbers.get(3)); + assertEquals(new Integer(5), numbers.get(4)); + } + + @Test + public void oneMillionGreatestMin() { + MinK<Integer> minFiveNumbers = new MinK<Integer>(5, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + minFiveNumbers.offer(n); + } + + assertEquals(new Integer(5), minFiveNumbers.greatestSmall()); + } + + @Test + public void oneMillionTwoTimesTop() { + TopK<Integer> topThreeNumbers = new TopK<Integer>(3, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + topThreeNumbers.offer(n); + topThreeNumbers.offer(n); + } + + List<Integer> numbers = topThreeNumbers.retrieve(); + assertEquals(new Integer(1000000), numbers.get(0)); + assertEquals(new Integer(1000000), numbers.get(1)); + assertEquals(new Integer(999999), numbers.get(2)); + } + + @Test + public void oneMillionTwoTimesMin() { + MinK<Integer> minThreeNumbers = new MinK<Integer>(3, new IntComparator()); + for (int n = 1; n <= 1000000; n++) { + minThreeNumbers.offer(n); + minThreeNumbers.offer(n); + } + + List<Integer> numbers = minThreeNumbers.retrieve(); + assertEquals(new Integer(1), numbers.get(0)); + assertEquals(new Integer(1), numbers.get(1)); + assertEquals(new Integer(2), numbers.get(2)); + } +} \ No newline at end of file
