opennlp.tools.ml.model.AbstractModelReader 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.model;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.StringTokenizer;
import java.util.zip.GZIPInputStream;
public abstract class AbstractModelReader {
/**
* The number of predicates contained in the model.
*/
protected int NUM_PREDS;
protected DataReader dataReader;
public AbstractModelReader(File f) throws IOException {
String filename = f.getName();
InputStream input;
// handle the zipped/not zipped distinction
if (filename.endsWith(".gz")) {
input = new GZIPInputStream(new FileInputStream(f));
filename = filename.substring(0,filename.length() - 3);
}
else {
input = new FileInputStream(f);
}
// handle the different formats
if (filename.endsWith(".bin")) {
this.dataReader = new BinaryFileDataReader(input);
}
else { // filename ends with ".txt"
this.dataReader = new PlainTextFileDataReader(input);
}
}
public AbstractModelReader(DataReader dataReader) {
super();
this.dataReader = dataReader;
}
/**
* Implement as needed for the format the model is stored in.
*/
public int readInt() throws java.io.IOException {
return dataReader.readInt();
}
/**
* Implement as needed for the format the model is stored in.
*/
public double readDouble() throws java.io.IOException {
return dataReader.readDouble();
}
/**
* Implement as needed for the format the model is stored in.
*/
public String readUTF() throws java.io.IOException {
return dataReader.readUTF();
}
public AbstractModel getModel() throws IOException {
checkModelType();
return constructModel();
}
public abstract void checkModelType() throws java.io.IOException;
public abstract AbstractModel constructModel() throws java.io.IOException;
protected String[] getOutcomes() throws java.io.IOException {
int numOutcomes = readInt();
String[] outcomeLabels = new String[numOutcomes];
for (int i = 0; i < numOutcomes; i++) outcomeLabels[i] = readUTF();
return outcomeLabels;
}
protected int[][] getOutcomePatterns() throws java.io.IOException {
int numOCTypes = readInt();
int[][] outcomePatterns = new int[numOCTypes][];
for (int i = 0; i < numOCTypes; i++) {
StringTokenizer tok = new StringTokenizer(readUTF(), " ");
int[] infoInts = new int[tok.countTokens()];
for (int j = 0; tok.hasMoreTokens(); j++) {
infoInts[j] = Integer.parseInt(tok.nextToken());
}
outcomePatterns[i] = infoInts;
}
return outcomePatterns;
}
protected String[] getPredicates() throws java.io.IOException {
NUM_PREDS = readInt();
String[] predLabels = new String[NUM_PREDS];
for (int i = 0; i < NUM_PREDS; i++)
predLabels[i] = readUTF();
return predLabels;
}
/**
* Reads the parameters from a file and populates an array of context objects.
* @param outcomePatterns The outcomes patterns for the model. The first index refers to which
* outcome pattern (a set of outcomes that occurs with a context) is being specified. The
* second index specifies the number of contexts which use this pattern at index 0, and the
* index of each outcomes which make up this pattern in indicies 1-n.
* @return An array of context objects.
* @throws java.io.IOException when the model file does not match the outcome patterns or can not be read.
*/
protected Context[] getParameters(int[][] outcomePatterns) throws java.io.IOException {
Context[] params = new Context[NUM_PREDS];
int pid = 0;
for (int i = 0; i < outcomePatterns.length; i++) {
//construct outcome pattern
int[] outcomePattern = new int[outcomePatterns[i].length - 1];
System.arraycopy(outcomePatterns[i], 1, outcomePattern, 0, outcomePatterns[i].length - 1);
//populate parameters for each context which uses this outcome pattern.
for (int j = 0; j < outcomePatterns[i][0]; j++) {
double[] contextParameters = new double[outcomePatterns[i].length - 1];
for (int k = 1; k < outcomePatterns[i].length; k++) {
contextParameters[k - 1] = readDouble();
}
params[pid] = new Context(outcomePattern,contextParameters);
pid++;
}
}
return params;
}
}