1. /* ===========================================================

  2.  * JFreeChart : a free chart library for the Java(tm) platform

  3.  * ===========================================================

  4.  *

  5.  * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.

  6.  *

  7.  * Project Info:  http://www.jfree.org/jfreechart/index.html

  8.  *

  9.  * This library is free software; you can redistribute it and/or modify it 

  10.  * under the terms of the GNU Lesser General Public License as published by 

  11.  * the Free Software Foundation; either version 2.1 of the License, or 

  12.  * (at your option) any later version.

  13.  *

  14.  * This library is distributed in the hope that it will be useful, but 

  15.  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 

  16.  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 

  17.  * License for more details.

  18.  *

  19.  * You should have received a copy of the GNU Lesser General Public License 

  20.  * along with this library; if not, write to the Free Software Foundation, 

  21.  * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.

  22.  *

  23.  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

  24.  * in the United States and other countries.]

  25.  *

  26.  * -------------------

  27.  * LineFunction2D.java

  28.  * -------------------

  29.  * (C) Copyright 2002-2005, by Object Refinery Limited.

  30.  *

  31.  * Original Author:  David Gilbert (for Object Refinery Limited);

  32.  * Contributor(s):   -;

  33.  *

  34.  * $Id: LineFunction2D.java,v 1.3 2005/02/24 10:44:45 mungady Exp $

  35.  *

  36.  * Changes:

  37.  * --------

  38.  * 01-Oct-2002 : Version 1 (DG);

  39.  *

  40.  */

  41. 

  42. package org.jfree.data.function;

  43. 

  44. 

  45. /**

  46.  * A function in the form y = a + bx.

  47.  */

  48. public class LineFunction2D implements Function2D {

  49. 

  50.     /** The intercept. */

  51.     private double a;

  52. 

  53.     /** The slope of the line. */

  54.     private double b;

  55. 

  56.     /**

  57.      * Constructs a new line function.

  58.      *

  59.      * @param a  the intercept.

  60.      * @param b  the slope.

  61.      */

  62.     public LineFunction2D(double a, double b) {

  63.         this.a = a;

  64.         this.b = b;

  65.     }

  66. 

  67.     /**

  68.      * Returns the function value.

  69.      *

  70.      * @param x  the x-value.

  71.      *

  72.      * @return The value.

  73.      */

  74.     public double getValue(double x) {

  75.         return this.a + this.b * x;

  76.     }

  77. 

  78. }