datautilities.java

Web图形化的Java库

/* ======================================
 * JFreeChart : a free Java chart library
 * ======================================
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 * Project Lead:  David Gilbert ([e-mail]);
 *
 * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * ------------------
 * DataUtilities.java
 * ------------------
 * (C) Copyright 2003, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: DataUtilities.java,v 1.3 2003/06/13 15:46:39 mungady Exp $
 *
 * Changes
 * -------
 * 05-Mar-2003 : Version 1 (DG);
 *
 */

package org.jfree.data;

/**
 * Utility methods for use with some of the data classes (but not the datasets, see
 * {@link DatasetUtilities}).
 *
 * @author David Gilbert
 */
public class DataUtilities {

    /**
     * Returns a {@link KeyedValues} instance that contains the cumulative percentage values
     * for the data in another {@link KeyedValues} instance.
     * <p>
     * The percentages are values between 0.0 and 1.0 (where 1.0 = 100%).
     *
     * @param data  the data.
     *
     * @return The cumulative percentages.
     */
    public static KeyedValues getCumulativePercentages(KeyedValues data) {

        DefaultKeyedValues result = new DefaultKeyedValues();

        double total = 0.0;
        for (int i = 0; i < data.getItemCount(); i++) {
            Number v = data.getValue(i);
            if (v != null) {
                total = total + v.doubleValue();
            }
        }

        double runningTotal = 0.0;
        for (int i = 0; i < data.getItemCount(); i++) {
            Number v = data.getValue(i);
            if (v != null) {
                runningTotal = runningTotal + v.doubleValue();
            }
            result.addValue(data.getKey(i), new Double(runningTotal / total));
        }

        return result;

    }

}