/*
* 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 opennlp.maxent;
import java.io.StringReader;
import junit.framework.TestCase;
import opennlp.model.EventStream;
import opennlp.model.MaxentModel;
import opennlp.model.OnePassRealValueDataIndexer;
import opennlp.model.RealValueFileEventStream;
public class ScaleDoesntMatterTest extends TestCase {
/**
* This test sets out to prove that the scale you use on real valued
* predicates doesn't matter when it comes the probability assigned to each
* outcome. Strangely, if we use (1,2) and (10,20) there's no difference. If
* we use (0.1,0.2) and (10,20) there is a difference.
*
* @throws Exception
*/
public void testScaleResults() throws Exception {
String smallValues = "predA=0.1 predB=0.2 A\n" + "predB=0.3 predA=0.1 B\n";
String smallTest = "predA=0.2 predB=0.2";
String largeValues = "predA=10 predB=20 A\n" + "predB=30 predA=10 B\n";
String largeTest = "predA=20 predB=20";
StringReader smallReader = new StringReader(smallValues);
EventStream smallEventStream = new RealBasicEventStream(
new PlainTextByLineDataStream(smallReader));
MaxentModel smallModel = GIS.trainModel(100,
new OnePassRealValueDataIndexer(smallEventStream, 0), false);
String[] contexts = smallTest.split(" ");
float[] values = RealValueFileEventStream.parseContexts(contexts);
double[] smallResults = smallModel.eval(contexts, values);
String smallResultString = smallModel.getAllOutcomes(smallResults);
System.out.println("smallResults: " + smallResultString);
StringReader largeReader = new StringReader(largeValues);
EventStream largeEventStream = new RealBasicEventStream(
new PlainTextByLineDataStream(largeReader));
MaxentModel largeModel = GIS.trainModel(100,
new OnePassRealValueDataIndexer(largeEventStream, 0), false);
contexts = largeTest.split(" ");
values = RealValueFileEventStream.parseContexts(contexts);
double[] largeResults = largeModel.eval(contexts, values);
String largeResultString = smallModel.getAllOutcomes(largeResults);
System.out.println("largeResults: " + largeResultString);
assertEquals(smallResults.length, largeResults.length);
for (int i = 0; i < smallResults.length; i++) {
System.out.println(String.format(
"classifiy with smallModel: %1$s = %2$f", smallModel.getOutcome(i),
smallResults[i]));
System.out.println(String.format(
"classifiy with largeModel: %1$s = %2$f", largeModel.getOutcome(i),
largeResults[i]));
assertEquals(smallResults[i], largeResults[i], 0.01f);
}
}
}