/*
* Copyright 2010
* Ubiquitous Knowledge Processing (UKP) Lab
* Technische Universität Darmstadt
*
* Licensed 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 de.tudarmstadt.ukp.dkpro.core.frequency;
import java.util.Arrays;
import java.util.Iterator;
import de.tudarmstadt.ukp.dkpro.core.api.frequency.provider.FrequencyCountProvider;
import edu.berkeley.nlp.lm.NgramLanguageModel;
import edu.berkeley.nlp.lm.io.LmReaders;
/**
* Wrapper for the Berkeley LM package.
*
* nGram index files are looked up in DKPRO_HOME directory.
*/
public class BerkeleyLmProvider
implements FrequencyCountProvider
{
private final NgramLanguageModel<String> lm;
private String language;
public BerkeleyLmProvider(String binaryFile, String language)
throws Exception
{
lm = LmReaders.readLmBinary(binaryFile);
this.language = language;
}
// FIXME how to obtain phrase count from logProb
@Override
public long getFrequency(String phrase)
{
throw new UnsupportedOperationException("Not implemented yet.");
// return getProbnew Float(Math.exp(logProb)).longValue();
}
@Override
public double getProbability(String phrase)
{
return Math.exp(getLogProbability(phrase));
}
@Override
public double getLogProbability(String phrase)
{
return lm.getLogProb(Arrays.asList(phrase.split(" ")));
}
@Override
public long getNrOfTokens()
{
return lm.getWordIndexer().numWords();
}
@Override
public long getNrOfNgrams(int n)
{
throw new UnsupportedOperationException("Not implemented yet.");
}
@Override
public long getNrOfDistinctNgrams(int n)
{
throw new UnsupportedOperationException("Not implemented yet.");
}
@Override
public Iterator<String> getNgramIterator(int n)
{
throw new UnsupportedOperationException("Not implemented yet.");
}
@Override
public String getLanguage()
{
return this.language;
}
@Override
public String getID()
{
return this.getClass().getSimpleName();
}
}