001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert 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-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.xy;
038
039import java.io.Serializable;
040
041/**
042 * A vector.
043 */
044public class Vector implements Serializable {
045
046    /** The vector x. */
047    private double x;
048
049    /** The vector y. */
050    private double y;
051
052    /**
053     * Creates a new instance of {@code Vector}.
054     *
055     * @param x  the x-component.
056     * @param y  the y-component.
057     */
058    public Vector(double x, double y) {
059        this.x = x;
060        this.y = y;
061    }
062
063    /**
064     * Returns the x-value.
065     *
066     * @return The x-value.
067     */
068    public double getX() {
069        return this.x;
070    }
071
072    /**
073     * Returns the y-value.
074     *
075     * @return The y-value.
076     */
077    public double getY() {
078        return this.y;
079    }
080
081    /**
082     * Returns the length of the vector.
083     *
084     * @return The vector length.
085     */
086    public double getLength() {
087        return Math.sqrt((this.x * this.x) + (this.y * this.y));
088    }
089
090    /**
091     * Returns the angle of the vector.
092     *
093     * @return The angle of the vector.
094     */
095    public double getAngle() {
096        return Math.atan2(this.y, this.x);
097    }
098
099    /**
100     * Tests this vector for equality with an arbitrary object.
101     *
102     * @param obj  the object ({@code null} not permitted).
103     *
104     * @return A boolean.
105     */
106    @Override
107    public boolean equals(Object obj) {
108        if (obj == this) {
109            return true;
110        }
111        if (!(obj instanceof Vector)) {
112            return false;
113        }
114        Vector that = (Vector) obj;
115        if (this.x != that.x) {
116            return false;
117        }
118        if (this.y != that.y) {
119            return false;
120        }
121        return true;
122    }
123
124    /**
125     * Returns a hash code for this instance.
126     *
127     * @return A hash code.
128     */
129    @Override
130    public int hashCode() {
131        int result = 193;
132        long temp = Double.doubleToLongBits(this.x);
133        result = 37 * result + (int) (temp ^ (temp >>> 32));
134        temp = Double.doubleToLongBits(this.y);
135        result = 37 * result + (int) (temp ^ (temp >>> 32));
136        return result;
137    }
138
139}