opennlp.tools.ml.perceptron.PerceptronModelReader 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 opennlp.tools.ml.perceptron;
import java.io.File;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import opennlp.tools.ml.model.AbstractModel;
import opennlp.tools.ml.model.AbstractModelReader;
import opennlp.tools.ml.model.Context;
import opennlp.tools.ml.model.DataReader;
/**
* The base class for readers of {@link PerceptronModel models}.
* It assumes that models are saved in the following sequence:
*
*
Perceptron (model type identifier)
*
1. # of parameters ({@code int})
*
2. # of outcomes ({@code int})
*
* list of outcome names ({@code String})
*
3. # of different types of outcome patterns ({@code int})
*
* list of ({@code int} {@code int[]})
*
[# of predicates for which outcome pattern is true] [outcome pattern]
*
4. # of predicates ({@code int})
*
* list of predicate names ({@code String})
*
* @see PerceptronModel
* @see AbstractModelReader
*/
public class PerceptronModelReader extends AbstractModelReader {
private static final Logger logger = LoggerFactory.getLogger(PerceptronModelReader.class);
/**
* Initializes a {@link PerceptronModelReader} via a {@link File}.
*
* @param file The {@link File} that references the model to be read.
*
* @throws IOException Thrown if IO errors occurred.
*/
public PerceptronModelReader(File file) throws IOException {
super(file);
}
/**
* Initializes a {@link PerceptronModelReader} via a {@link DataReader}.
*
* @param dataReader The {@link DataReader} that references the model to be read.
*/
public PerceptronModelReader(DataReader dataReader) {
super(dataReader);
}
/**
* Constructs a {@link AbstractModel model}.
*
* If you are creating a reader for a format which won't work with this
* (perhaps a database or {@code xml} file), override this method and ignore the
* other methods provided in this abstract class.
*
* @return A {@link PerceptronModel} reconstructed from a model's (read) attributes.
* @throws IOException Thrown if IO errors occurred during (re-)construction.
*/
@Override
public AbstractModel constructModel() throws IOException {
String[] outcomeLabels = getOutcomes();
int[][] outcomePatterns = getOutcomePatterns();
String[] predLabels = getPredicates();
Context[] params = getParameters(outcomePatterns);
return new PerceptronModel(params, predLabels, outcomeLabels);
}
/**
* Reads the mode type from the underlying reader and informs if it not a
* {@code Perceptron} model.
*
* @throws IOException Thrown if IO errors occurred.
*/
@Override
public void checkModelType() throws IOException {
String modelType = readUTF();
if (!modelType.equals("Perceptron"))
logger.error("Attempting to load a {} " +
" model as a Perceptron model." +
" You should expect problems.", modelType);
}
}