/*
* 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.model;
import java.io.File;
import java.io.IOException;
import opennlp.maxent.GIS;
import opennlp.maxent.io.SuffixSensitiveGISModelWriter;
public class RealValueFileEventStream extends FileEventStream {
public RealValueFileEventStream(String fileName) throws IOException {
super(fileName);
}
public RealValueFileEventStream(File file) throws IOException {
super(file);
}
/**
* Parses the specified contexts and re-populates context array with features and returns the values
* for these features.
* If all values are unspecified, then null is returned.
* @param contexts The contexts with real values specified.
* @return The value for each context or null if all values are unspecified.
*/
public static float[] parseContexts(String[] contexts) {
boolean hasRealValue = false;
float[] values = new float[contexts.length];
for (int ci = 0; ci < contexts.length; ci++) {
int ei = contexts[ci].lastIndexOf("=");
if (ei > 0 && ei+1 < contexts[ci].length()) {
boolean gotReal = true;
try {
values[ci] = Float.parseFloat(contexts[ci].substring(ei+1));
}
catch (NumberFormatException e) {
gotReal = false;
System.err.println("Unable to determine value in context:"+contexts[ci]);
values[ci] = 1;
}
if (gotReal) {
if (values[ci] < 0) {
throw new RuntimeException("Negitive values are not allowed: "+contexts[ci]);
}
contexts[ci] = contexts[ci].substring(0,ei);
hasRealValue = true;
}
}
else {
values[ci] = 1;
}
}
if (!hasRealValue) {
values = null;
}
return values;
}
public Event next() {
int si = line.indexOf(' ');
String outcome = line.substring(0,si);
String[] contexts = line.substring(si+1).split(" ");
float[] values = parseContexts(contexts);
return (new Event(outcome, contexts, values));
}
/**
* Trains and writes a model based on the events in the specified event file.
* the name of the model created is based on the event file name.
* @param args eventfile [iterations cuttoff]
* @throws IOException when the eventfile can not be read or the model file can not be written.
*/
public static void main(String[] args) throws IOException {
if (args.length == 0) {
System.err.println("Usage: RealValueFileEventStream eventfile [iterations cutoff]");
System.exit(1);
}
int ai=0;
String eventFile = args[ai++];
EventStream es = new RealValueFileEventStream(eventFile);
int iterations = 100;
int cutoff = 5;
if (ai < args.length) {
iterations = Integer.parseInt(args[ai++]);
cutoff = Integer.parseInt(args[ai++]);
}
AbstractModel model = GIS.trainModel(iterations,new OnePassRealValueDataIndexer(es,cutoff));
new SuffixSensitiveGISModelWriter(model, new File(eventFile+".bin.gz")).persist();
}
}