opennlp.tools.ml.model.RealValueFileEventStream 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.IOException;
public class RealValueFileEventStream extends FileEventStream {
public RealValueFileEventStream(String fileName) throws IOException {
super(fileName);
}
public RealValueFileEventStream(String fileName, String encoding) throws IOException {
super(fileName, encoding);
}
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("Negative 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;
}
@Override
public Event read() throws IOException {
String line;
if ((line = reader.readLine()) != null) {
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);
}
return null;
}
}