/**
* 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.clustering.spectral;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.clustering.spectral.UnitVectorizerJob.UnitVectorizerMapper;
import org.apache.mahout.common.DummyRecordWriter;
import org.apache.mahout.common.MahoutTestCase;
import org.apache.mahout.math.RandomAccessSparseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.junit.Test;
public class TestUnitVectorizerJob extends MahoutTestCase {
private static final double [][] RAW = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9} };
@Test
public void testUnitVectorizerMapper() throws Exception {
UnitVectorizerMapper mapper = new UnitVectorizerMapper();
Configuration conf = getConfiguration();
// set up the dummy writers
DummyRecordWriter<IntWritable, VectorWritable> writer = new
DummyRecordWriter<IntWritable, VectorWritable>();
Mapper<IntWritable, VectorWritable, IntWritable, VectorWritable>.Context
context = DummyRecordWriter.build(mapper, conf, writer);
// perform the mapping
for (int i = 0; i < RAW.length; i++) {
Vector vector = new RandomAccessSparseVector(RAW[i].length);
vector.assign(RAW[i]);
mapper.map(new IntWritable(i), new VectorWritable(vector), context);
}
// check the results
assertEquals("Number of map results", RAW.length, writer.getData().size());
for (int i = 0; i < RAW.length; i++) {
IntWritable key = new IntWritable(i);
List<VectorWritable> list = writer.getValue(key);
assertEquals("Only one element per row", 1, list.size());
Vector v = list.get(0).get();
assertTrue("Unit vector sum is 1 or differs by 0.0001", Math.abs(v.norm(2) - 1) < 0.000001);
}
}
}