observationintegerreader.java

java实现的隐马尔科夫模型

/* jahmm package - v0.3.1 */

/*
 *  Copyright (c) 2004, Jean-Marc Francois.
 *
 *  This file is part of Jahmm.
 *  Jahmm is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  Jahmm is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Jahmm; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package be.ac.ulg.montefiore.run.jahmm.io;

import java.util.*;
import java.io.*;
import be.ac.ulg.montefiore.run.jahmm.*;


/**
 * Reads an {@link be.ac.ulg.montefiore.run.jahmm.ObservationInteger
 * ObservationInteger} up to (and including) a semi-colon.
 * <p>
 * The format of this observation is a simple integer ([+-]?[0123456789]+).
 * <p>
 * For example, reading
 * <pre>76;</pre>
 * creates an observation such as the one generated by
 * <code>new ObservationInteger(76);</code>
 */
public class ObservationIntegerReader
    extends ObservationReader {
    
    // Maximum number elements allowed
    private int nbElements;
    
    
    /**
     * Constructs a reader of {@link ObservationInteger ObservationInteger}.
     */
    public ObservationIntegerReader() {
	nbElements = -1;
    }
    
    
    /**
     * Constructs a reader of {@link ObservationInteger ObservationInteger}.
     * Verifies the maximum value of the observations read.
     *
     * @param nbElements The permitted number of different elements.  Each
     *                   value must be <code>0</code> &le; <code>value</code>
     *                   &lt; <code>nbElements</code>.
     */
    public ObservationIntegerReader(int nbElements) {
	if (nbElements <= 0)
	    throw new IllegalArgumentException("Nb of elements must be " +
					       "positive");
	
	this.nbElements = nbElements;
    }

    
    /**
     * An {@link be.ac.ulg.montefiore.run.jahmm.ObservationInteger
     * ObservationInteger} reader, as explained in 
     * {@link ObservationReader ObservationReader}.
     *
     * @param st A stream tokenizer.
     * @return The {@link be.ac.ulg.montefiore.run.jahmm.ObservationInteger
     *         ObservationInteger} read.
     */
    public Observation read(StreamTokenizer st) 
	throws IOException, FileFormatException {
	
	ObservationInteger oi;

	st.ordinaryChar((int)'.');

	switch (st.nextToken()) {
	case StreamTokenizer.TT_EOL:
	case StreamTokenizer.TT_EOF:
	case StreamTokenizer.TT_WORD:
	    throw new FileFormatException("Integer expected");
	    
	case StreamTokenizer.TT_NUMBER:
	    if (st.nval > nbElements)
		throw new FileFormatException("Integer higher than maxium " +
					      "value");
	    oi = new ObservationInteger((int) st.nval);
	    break;
	    
	default:
	    throw new FileFormatException("Integer expected");
	}
	
	switch (st.nextToken()) {
	case ';':
	    break;
	    
	default:
	    if (st.ttype != ';')
		throw new FileFormatException("';' expected");
	}
	
	ObservationSequencesReader.initSyntaxTable(st);
	return oi;
    }
}