    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    025 * Other names may be trademarks of their respective owners.]
    026 *
    027 * -----------
    028 * Vector.java
    029 * -----------
    030 * (C) Copyright 2007, 2008, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * Changes
    036 * -------
    037 * 30-Jan-2007 : Version 1 (DG);
    038 * 24-May-2007 : Added getLength() and getAngle() methods, thanks to
    039 *               matinh (DG);
    040 * 25-May-2007 : Moved from experimental to the main source tree (DG);
    041 *
    042 */
    043
    044package org.jfree.data.xy;
    045
    046import java.io.Serializable;
    047
    048/**
    049 * A vector.
    050 *
    051 * @since 1.0.6
    052 */
    053public class Vector implements Serializable {
    054
    055    /** The vector x. */
    056    private double x;
    057
    058    /** The vector y. */
    059    private double y;
    060
    061    /**
    062     * Creates a new instance of <code>Vector</code>.
    063     *
    064     * @param x  the x-component.
    065     * @param y  the y-component.
    066     */
    067    public Vector(double x, double y) {
    068        this.x = x;
    069        this.y = y;
    070    }
    071
    072    /**
    073     * Returns the x-value.
    074     *
    075     * @return The x-value.
    076     */
    077    public double getX() {
    078        return this.x;
    079    }
    080
    081    /**
    082     * Returns the y-value.
    083     *
    084     * @return The y-value.
    085     */
    086    public double getY() {
    087        return this.y;
    088    }
    089
    090    /**
    091     * Returns the length of the vector.
    092     *
    093     * @return The vector length.
    094     */
    095    public double getLength() {
    096        return Math.sqrt((this.x * this.x) + (this.y * this.y));
    097    }
    098
    099    /**
    100     * Returns the angle of the vector.
    101     *
    102     * @return The angle of the vector.
    103     */
    104    public double getAngle() {
    105        return Math.atan2(this.y, this.x);
    106    }
    107
    108    /**
    109     * Tests this vector for equality with an arbitrary object.
    110     *
    111     * @param obj  the object (<code>null</code> not permitted).
    112     *
    113     * @return A boolean.
    114     */
    115    public boolean equals(Object obj) {
    116        if (obj == this) {
    117            return true;
    118        }
    119        if (!(obj instanceof Vector)) {
    120            return false;
    121        }
    122        Vector that = (Vector) obj;
    123        if (this.x != that.x) {
    124            return false;
    125        }
    126        if (this.y != that.y) {
    127            return false;
    128        }
    129        return true;
    130    }
    131
    132    /**
    133     * Returns a hash code for this instance.
    134     *
    135     * @return A hash code.
    136     */
    137    public int hashCode() {
    138        int result = 193;
    139        long temp = Double.doubleToLongBits(this.x);
    140        result = 37 * result + (int) (temp ^ (temp >>> 32));
    141        temp = Double.doubleToLongBits(this.y);
    142        result = 37 * result + (int) (temp ^ (temp >>> 32));
    143        return result;
    144    }
    145
    146}