/*
* Copyright 2011
* 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.api.frequency.provider;
import java.io.IOException;
import java.util.Iterator;
public interface FrequencyCountProvider
{
/**
* Get frequency for a phrase
*
* @param phrase
* phrase to search
*
* @return frequency of the phrase. Returns 0 if the phrase does not exist in the corpus.
* @throws IOException
* if the information cannot be retrieved.
*/
public long getFrequency(String phrase)
throws IOException;
/**
* Get the probability (=normalized frequency) for a phrase.<br>
* The frequency count is normalized by the number of phrases in the corpus.
*
*
* @param phrase
* phrase to search
*
* @return probability (=normalized frequency) of the phrase. Returns null if the phrase does
* not exist in the corpus.
* @throws IOException
* if the information cannot be retrieved.
*/
public double getProbability(String phrase)
throws IOException;
/**
* Get the log probability for a phrase
*
* @param phrase
* phrase to search
*
* @return The log probability of the. Returns 0 if the phrase does not exist in the corpus.
* @throws IOException
* if the information cannot be retrieved.
*/
public double getLogProbability(String phrase)
throws IOException;
/**
* @return The number of tokens in the corpus.
* @throws IOException
* if the information cannot be retrieved.
*/
public long getNrOfTokens()
throws IOException;
/**
* Returns the number of ngrams of a given size in the corpus.
*
* @param n
* the ngram size.
* @return the number of ngrams.
* @throws IOException
* if the information cannot be retrieved.
*/
public long getNrOfNgrams(int n)
throws IOException;
/**
* Returns the number of distinct ngrams of a given size in the corpus.
*
* @param n
* the ngram size.
* @return the number of ngrams.
* @throws IOException
* if the information cannot be retrieved.
*/
public long getNrOfDistinctNgrams(int n)
throws IOException;
/**
* Returns an iterator over all ngrams of a given size in the corpus.
*
* @param n
* the ngram size.
* @return an iterator over the ngrams.
* @throws IOException
* if the information cannot be retrieved.
*/
public Iterator<String> getNgramIterator(int n)
throws IOException;
/**
* Returns the language for which the frequencies are provided.
*
* @return the language.
* @throws IOException
* if the information cannot be retrieved.
*/
public String getLanguage()
throws IOException;
/**
* Returns an ID that identifies the frequency provider
*
* @return the ID.
*/
public String getID();
}