org.apache.mahout.classifier.sequencelearning.hmm.ViterbiEvaluator Maven / Gradle / Ivy
/**
* 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.classifier.sequencelearning.hmm;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import org.apache.commons.cli2.CommandLine;
import org.apache.commons.cli2.Group;
import org.apache.commons.cli2.Option;
import org.apache.commons.cli2.OptionException;
import org.apache.commons.cli2.builder.ArgumentBuilder;
import org.apache.commons.cli2.builder.DefaultOptionBuilder;
import org.apache.commons.cli2.builder.GroupBuilder;
import org.apache.commons.cli2.commandline.Parser;
import org.apache.commons.io.Charsets;
import org.apache.mahout.common.CommandLineUtil;
import org.apache.mahout.common.commandline.DefaultOptionCreator;
/**
* Command-line tool for Viterbi evaluating
*/
public final class ViterbiEvaluator {
private ViterbiEvaluator() {
}
public static void main(String[] args) throws IOException {
DefaultOptionBuilder optionBuilder = new DefaultOptionBuilder();
ArgumentBuilder argumentBuilder = new ArgumentBuilder();
Option inputOption = DefaultOptionCreator.inputOption().create();
Option outputOption = DefaultOptionCreator.outputOption().create();
Option modelOption = optionBuilder.withLongName("model").
withDescription("Path to serialized HMM model").
withShortName("m").withArgument(argumentBuilder.withMaximum(1).withMinimum(1).
withName("path").create()).withRequired(true).create();
Option likelihoodOption = optionBuilder.withLongName("likelihood").
withDescription("Compute likelihood of observed sequence").
withShortName("l").withRequired(false).create();
Group optionGroup = new GroupBuilder().withOption(inputOption).
withOption(outputOption).withOption(modelOption).withOption(likelihoodOption).
withName("Options").create();
try {
Parser parser = new Parser();
parser.setGroup(optionGroup);
CommandLine commandLine = parser.parse(args);
String input = (String) commandLine.getValue(inputOption);
String output = (String) commandLine.getValue(outputOption);
String modelPath = (String) commandLine.getValue(modelOption);
boolean computeLikelihood = commandLine.hasOption(likelihoodOption);
//reading serialized HMM
;
HmmModel model;
try (DataInputStream modelStream = new DataInputStream(new FileInputStream(modelPath))) {
model = LossyHmmSerializer.deserialize(modelStream);
}
//reading observations
List observations = new ArrayList<>();
try (Scanner scanner = new Scanner(new FileInputStream(input), "UTF-8")) {
while (scanner.hasNextInt()) {
observations.add(scanner.nextInt());
}
}
int[] observationsArray = new int[observations.size()];
for (int i = 0; i < observations.size(); ++i) {
observationsArray[i] = observations.get(i);
}
//decoding
int[] hiddenStates = HmmEvaluator.decode(model, observationsArray, true);
//writing output
try (PrintWriter writer =
new PrintWriter(new OutputStreamWriter(new FileOutputStream(output), Charsets.UTF_8), true)) {
for (int hiddenState : hiddenStates) {
writer.print(hiddenState);
writer.print(' ');
}
}
if (computeLikelihood) {
System.out.println("Likelihood: " + HmmEvaluator.modelLikelihood(model, observationsArray, true));
}
} catch (OptionException e) {
CommandLineUtil.printHelp(optionGroup);
}
}
}