001 /* =========================================================== 002 * JFreeChart : a free chart library for the Java(tm) platform 003 * =========================================================== 004 * 005 * (C) Copyright 2000-2005, 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 * LineFunction2D.java 029 * ------------------- 030 * (C) Copyright 2002-2005, by Object Refinery Limited. 031 * 032 * Original Author: David Gilbert (for Object Refinery Limited); 033 * Contributor(s): -; 034 * 035 * $Id: LineFunction2D.java,v 1.3.2.1 2005/10/25 21:31:32 mungady Exp $ 036 * 037 * Changes: 038 * -------- 039 * 01-Oct-2002 : Version 1 (DG); 040 * 041 */ 042 043 package org.jfree.data.function; 044 045 046 /** 047 * A function in the form y = a + bx. 048 */ 049 public class LineFunction2D implements Function2D { 050 051 /** The intercept. */ 052 private double a; 053 054 /** The slope of the line. */ 055 private double b; 056 057 /** 058 * Constructs a new line function. 059 * 060 * @param a the intercept. 061 * @param b the slope. 062 */ 063 public LineFunction2D(double a, double b) { 064 this.a = a; 065 this.b = b; 066 } 067 068 /** 069 * Returns the function value. 070 * 071 * @param x the x-value. 072 * 073 * @return The value. 074 */ 075 public double getValue(double x) { 076 return this.a + this.b * x; 077 } 078 079 }