001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it
010     * under the terms of the GNU Lesser General Public License as published by
011     * the Free Software Foundation; either version 2.1 of the License, or
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022     * USA.
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025     * in the United States and other countries.]
026     *
027     * ---------------
028     * Function2D.java
029     * ---------------
030     * (C) Copyright 2002-2008, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes:
036     * --------
037     * 01-Oct-2002 : Version 1 (DG);
038     * 20-Jan-2005 : Minor Javadoc update (DG);
039     *
040     */
041    
042    package org.jfree.data.function;
043    
044    /**
045     * A function of the form <code>y = f(x)</code>.
046     */
047    public interface Function2D {
048    
049        /**
050         * Returns the value of the function ('y') for a given input ('x').
051         *
052         * @param x  the x-value.
053         *
054         * @return The function value.
055         */
056        public double getValue(double x);
057    
058    }