/*
 * @(#)Tabulator.java           0.0.1 99/07/30
 *
 * Copyright (c) 1999 by Willie Wheeler.  All rights reserved.
 */
package stats;

import java.util.*;
import javax.swing.event.*;
import lang.*;

/**
 * ...
 * <p>06/02/99: We need to optimize <tt>tableChanged()</tt> so that we don't
 * retabulate from scratch when <tt>INSERT</tt> events come in.
 *
 * @version     0.0.1 07/30/99
 * @author      Willie Wheeler
 */
public class Tabulator implements TableModelListener {
    static boolean			debug = false;

    /** @serial */
    protected DataTableModel		dataIn;

    /** @serial */
    protected int[]			varIndices;

    /** @serial */
    protected ContingencyTableModel	dataOut;

    /**
     * Builds a tabulator to compute the joint frequency and probability
     * distributions for <em>all</em> variables in the specified data table.
     * This assumes that all of the variables are <tt>TextVariable</tt>s.
     *
     * @param   dataIn          data table over which to compute the joint
     *                          frequency and probability distributions
     */
    public Tabulator(DataTableModel dataIn) { setDataIn(dataIn); }
    
    /**
     * Builds a tabulator to compute the joint frequency and probability
     * distributions for a restricted list of variables in the specified data
     * table.
     *
     * @param   dataIn          data table over which to compute the joint
     *                          frequency and probability distributions
     * @param   variableIndices array of variable indices
     */
    public Tabulator(DataTableModel dataIn, int[] variableIndices) {
	setDataIn(dataIn, variableIndices);
    }

    public void setDataIn(DataTableModel dataIn) {
	int numVars = dataIn.getColumnCount();
	varIndices = new int[numVars];
	for (int i = 0; i < numVars; i++) { varIndices[i] = i; }
	setDataIn(dataIn, varIndices);
    }

    public void setDataIn(DataTableModel dataIn, int[] variableIndices) {

	// Install the new dataIn, etc.
	if (this.dataIn != null) {
	    this.dataIn.removeTableModelListener(this);
	}
	this.dataIn = dataIn;
	dataIn.addTableModelListener(this);
	this.varIndices = variableIndices;

	// Build and install a new dataOut.
	Vector factors = new Vector();
	for (int i = 0; i < varIndices.length; i++) {
	    factors.add((TextVariable)dataIn.getVariable(i));
	}
	dataOut = new ContingencyTableModel(factors);
	tabulate();
    }

    public void tabulate() {
	int numFactors = varIndices.length;
	int numData = dataIn.getNumData();
	int numTotalStates = dataOut.getRowCount();

	// Build and fill an array of frequencies.
	int[] freqs = new int[numTotalStates];
	for (int i = 0; i < numData; i++) {
      
	    // Build the current total state.
	    int[] totalState = new int[numFactors];
	    for (int j = 0; j < numFactors; j++) {
		Object value = dataIn.getValueAt(i, varIndices[j]);
		totalState[j] = ((Integer)value).intValue();
	    }

	    // Increment the state's frequency.
	    freqs[dataOut.rowIndex(totalState)]++;
	}

	// Put frequencies and estimates into dataOut.
	Vector tableData = dataOut.getDataVector();
	for (int i = 0; i < numTotalStates; i++) {
	    Vector rowData = (Vector)tableData.get(i);
	    rowData.set(dataOut.getFrequencyColumnIndex(),
			new Integer(freqs[i]));
	}

	// Update the estimates.
	dataOut.updateEstimates();
    }

    public ContingencyTableModel getDataOut() { return dataOut; }

    public void tableChanged(TableModelEvent e) { tabulate(); }
}