source: trunk/EventBenchConsole/src/de/ugoe/cs/eventbench/commands/CMDgenerateFixedLengthSequences.java @ 171

package de.ugoe.cs.eventbench.commands;

import java.security.InvalidParameterException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;
import java.util.Set;

import de.ugoe.cs.eventbench.data.Event;
import de.ugoe.cs.eventbench.data.GlobalDataContainer;
import de.ugoe.cs.eventbench.models.IStochasticProcess;
import de.ugoe.cs.util.console.Command;
import de.ugoe.cs.util.console.Console;

/**
 * <p>
 * Command to generate all sequences of a given length.
 * </p>
 * 
 * @author Steffen Herbold
 * @version 1.0
 */
public class CMDgenerateFixedLengthSequences implements Command {

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.util.console.Command#run(java.util.List)
         */
        @Override
        public void run(List<Object> parameters) {
                String modelname;
                String sequencesName;
                int minLength;
                int maxLength;
                boolean all = true;
                int numSequences = -1;
                try {
                        modelname = (String) parameters.get(0);
                        sequencesName = (String) parameters.get(1);
                        minLength = Integer.parseInt((String) parameters.get(2));
                        maxLength = Integer.parseInt((String) parameters.get(3));
                        if (parameters.size() >= 5) {
                                all = Boolean.parseBoolean((String) parameters.get(4));
                        }
                        if (parameters.size() == 6) {
                                numSequences = Integer.parseInt((String) parameters.get(5));
                        }
                } catch (Exception e) {
                        throw new InvalidParameterException();
                }

                IStochasticProcess model = null;
                Object dataObject = GlobalDataContainer.getInstance()
                                .getData(modelname);
                if (dataObject == null) {
                        Console.println("Model " + modelname + " not found in storage.");
                } else if (!(dataObject instanceof IStochasticProcess)) {
                        Console.println("Object " + modelname + " not of type MarkovModel!");
                } else {
                        model = (IStochasticProcess) dataObject;
                        Collection<List<? extends Event<?>>> sequences = new LinkedHashSet<List<? extends Event<?>>>();
                        for (int length = minLength; length <= maxLength; length++) {
                                sequences.addAll(model.generateValidSequences(length + 2));
                        }
                        Console.traceln("" + sequences.size() + " possible");
                        if (!all && numSequences < sequences.size()) {
                                List<Double> probabilities = new ArrayList<Double>(
                                                sequences.size());
                                double probSum = 0.0;
                                for (List<? extends Event<?>> sequence : sequences) {
                                        double prob = model.getProbability(sequence);
                                        probabilities.add(prob);
                                        probSum += prob;
                                }
                                Set<Integer> drawnSequences = new HashSet<Integer>(numSequences);
                                Random r = new Random();
                                while (drawnSequences.size() < numSequences) {
                                        double randVal = r.nextDouble() * probSum;
                                        double sum = 0.0d;
                                        int index = -1;
                                        while (sum < randVal) {
                                                index++;
                                                double currentProb = probabilities.get(index);
                                                sum += currentProb;
                                        }
                                        if (!drawnSequences.contains(index)) {
                                                drawnSequences.add(index);
                                                probSum -= probabilities.get(index);
                                                probabilities.set(index, 0.0d);
                                        }
                                }
                                Collection<List<? extends Event<?>>> retainedSequences = new LinkedList<List<? extends Event<?>>>();
                                int index = 0;
                                for (List<? extends Event<?>> sequence : sequences) {
                                        if (drawnSequences.contains(index)) {
                                                retainedSequences.add(sequence);
                                        }
                                        index++;
                                }
                                sequences = retainedSequences;
                        }
                        if (GlobalDataContainer.getInstance().addData(sequencesName,
                                        sequences)) {
                                Console.traceln("Old data \"" + sequencesName
                                                + "\" overwritten");
                        }
                        Console.println("" + sequences.size() + " sequences generated");
                }
        }

        /*
         * (non-Javadoc)
         * 
         * @see de.ugoe.cs.util.console.Command#help()
         */
        @Override
        public void help() {
                Console.println("Usage: generateFixedLengthSequences <modelname> <sequencesName> <length> {<all>} {<numSequences>}");
        }

}