package dragon.ir.search.smooth;import dragon.ir.index.IRDoc;import dragon.ir.query.SimpleTermPredicate;/** * <p>Interface of smoother which returns a score of a searching term in the given document to the searcher</p> * <p>The toolkit has implemented various language model smoothing methods as well as traditional probabilistic and vector space models. * For language models, the score means the probability of the doucment generating the term.</p> * <p>Copyright: Copyright (c) 2005</p> * <p>Company: IST, Drexel University</p> * @author Davis Zhou * @version 1.0 */public interface Smoother {    /**     * @param doc the document     * @param queryTerm the query term     * @param termFreq the frequency of the query term in the given document     * @return a score     */    public double getSmoothedProb(IRDoc doc, SimpleTermPredicate queryTerm, int termFreq);    /**     * This method is equal to call getSmoothedProb(doc, queryTerm, 0).     * @param doc the document     * @param queryTerm the query term     * @return a score     */    public double getSmoothedProb(IRDoc doc, SimpleTermPredicate queryTerm);    /**     * Before calling this method, one should call the setQueryTerm method.     * @param doc the document     * @param termFreq the frequency of the current query term in the given document     * @return a score     */    public double getSmoothedProb(IRDoc doc, int termFreq);    /**     * Before calling this method, one should call the setDoc method.     * @param queryTerm the query term     * @param termFreq the frequency of the given query term in the current document     * @return a score     */    public double getSmoothedProb(SimpleTermPredicate queryTerm, int termFreq);    /**     *Before calling this method, one should call the setQueryTerm method and the setDoc method.     * @param termFreq the frequency of the current term in the current document     * @return a score     */    public double getSmoothedProb(int termFreq);    /**     * It is equal to calling getSmoothedProb(queryTerm, 0);     * @param queryTerm the query term     * @return a score     */    public double getSmoothedProb(SimpleTermPredicate queryTerm);    /**     * It is equal to calling getSmoothedProb(doc, 0);     * @param doc the document     * @return a score     */    public double getSmoothedProb(IRDoc doc);    /**     * @param params paramteres for the current smoother     * @return true if successful     */    public boolean setParameters(double[] params);    /**     * Set the current query term for processing     * @param queryTerm the query term     */    public void setQueryTerm(SimpleTermPredicate queryTerm);    /**     * Set the current document for processing     * @param doc the document     */    public void setDoc(IRDoc doc);    /**     * If this method returns true, the fullrank searcher will do breadth-frist search, i.e. processing document one by one.     * @return true or false     */    public boolean isDocFirstOptimal();    /**     * If this method returns true, the fullrank searcher will do depth-frist search, i.e. processing query terms one by one and then merging     * the document lists resulted from different query terms.     * @return true or false     */    public boolean isQueryTermFirstOptimal();    /**     * If this option is true, smoomther will return a log score     * @param option true or false     */    public void setLogLikelihoodOption(boolean option);    public boolean getLogLikelihoodOption();}