Fill in the TODO blanks in ModelMatcher.java and MatcherController.java

//ModelMatcher.java

import java.util.HashMap; import java.util.Collection; import java.util.ArrayList; import java.util.Arrays;

/** * Report the average log likelihood of a test String occuring in a * given Markov model and detail the calculated values behind this statistic. * * @author * @version */ public class ModelMatcher {

/** log likelihoods for a teststring under a given model */ private HashMap logLikelihoodMap; /** summary statistic for this setting */ private double averageLogLikelihood; /** * Constructor to initialise the fields for the log likelihood map for * a test string and a given Markov model and * the average log likelihood summary statistic * @param MarkovModel model a given Markov model object * @param String teststring */ public ModelMatcher(MarkovModel model, String testString) { //TODO }

/** Helper method that calculates the average log likelihood statistic * given a HashMap of strings and their Laplace probabilities * and the total number of ngrams in the model. * * @param logs map of ngram strings and their log likelihood * @param ngramCount int number of ngrams in the original test string * @return average log likelihood: the total of loglikelihoods * divided by the ngramCount */ private double averageLogLikelihood(HashMap logs, int ngramCount) { //TODO return 0.1; } /** Helper method to calculate the total log likelihood statistic * given a HashMap of strings and their Laplace probabilities * and the total number of ngrams in the model. * * @param logs map of ngram strings and their log likelihood * @return total log likelihood: the sum of loglikelihoods in logs */ private double totalLogLikelihood(HashMap logs) { //TODO return 0.1; }

/** * @return the average log likelihood statistic */ public double getAverageLogLikelihood() { return averageLogLikelihood; } /** * @return the log likelihood value for a given ngram from the input string */ public double getLogLikelihood(String ngram) { return (logLikelihoodMap.get(ngram)); } /** * Make a String summarising the log likelihood map and its statistics * @return String of ngrams and their loglikeihood differences between the models * The likelihood table should be ordered from highest to lowest likelihood */ public String toString() { //TODO return null; }

}

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//MatcherController.java

import java.io.File; import java.util.ArrayList; import java.util.HashMap; import java.util.Set; import java.io.*;

/** Create and manipulate Markov models and model matchers for lists of training data * a test data String and generate output from it for convenient display. * * @author * @version * */ public class MatcherController {

/** list of training data string used to generate markov models */ ArrayList trainingDataList; /** test data to be matched with the models */ String testData; /** order of the markov models*/ int k; /** generated list of markov models for the given training data*/ ArrayList modelList; /** generated list of matchers for the given markov models and test data*/ ArrayList matcherList;

/** Generate models for analysis * @param k order of the markov models to be used * @param testData String to check against different models * @throw unchecked exceptions if the input order or data inputs are invalid */ public MatcherController(int k, ArrayList trainingDataList, String testData) { //TODO }

/** @return a string containing all lines from a file * ff file contents can be got, otherwise null * This method should process any exceptions that arise. */ private static String getFileContents(String filename) { //TODO return null; }

/** * @return the ModelMatcher object that has the highest average loglikelihood * (where all candidates are trained for the same test string */ public ModelMatcher getBestMatch(ArrayList candidates) { //TODO return null; }

/** @return String an *explanation* of * why the test string is the match from the candidate models */ public String explainBestMatch(ModelMatcher best) { //TODO return null; }

/** Display an error to the user in a manner appropriate * for the interface being used. * * @param message */ public void displayError(String message) { // LEAVE THIS METHOD EMPTY }

}