/* Copyright (C) 2002 Univ. of Massachusetts Amherst, Computer Science Dept.
This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
http://www.cs.umass.edu/~mccallum/mallet
This software is provided under the terms of the Common Public License,
version 1.0, as published by http://www.opensource.org. For further
information, see the file `LICENSE' included with this distribution. */
/**
@author Aron Culotta <a href="mailto:culotta@cs.umass.edu">culotta@cs.umass.edu</a>
*/
package cc.mallet.fst.confidence;
import java.util.logging.*;
import java.util.*;
import cc.mallet.fst.*;
import cc.mallet.pipe.iterator.*;
import cc.mallet.types.*;
import cc.mallet.util.MalletLogger;
/**
Estimates the confidence of an entire sequence by combining the
output of a segment confidence estimator for each segment.
*/
public class SegmentProductConfidenceEstimator extends TransducerSequenceConfidenceEstimator
{
TransducerConfidenceEstimator segmentEstimator;
private static Logger logger = MalletLogger.getLogger(
SegmentProductConfidenceEstimator.class.getName());
public SegmentProductConfidenceEstimator (Transducer model,
TransducerConfidenceEstimator segmentConfidenceEstimator) {
super(model);
this.segmentEstimator = segmentConfidenceEstimator;
}
/**
Calculates the confidence in the tagging of a {@link Instance}.
*/
public double estimateConfidenceFor (Instance instance,
Object[] startTags,
Object[] inTags) {
SegmentIterator iter = new SegmentIterator (model, instance, startTags, inTags);
double instanceConfidence = 1;
while (iter.hasNext()) {
Segment s = (Segment) iter.nextSegment();
instanceConfidence *= segmentEstimator.estimateConfidenceFor (s);
}
return instanceConfidence;
}
}