Frames | No Frames |
1: /* =========================================================== 2: * JFreeChart : a free chart library for the Java(tm) platform 3: * =========================================================== 4: * 5: * (C) Copyright 2000-2007, 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 20: * License along with this library; if not, write to the Free Software 21: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 22: * USA. 23: * 24: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 25: * in the United States and other countries.] 26: * 27: * ----------------------------- 28: * MeanAndStandardDeviation.java 29: * ----------------------------- 30: * (C) Copyright 2003-2007, by Object Refinery Limited. 31: * 32: * Original Author: David Gilbert (for Object Refinery Limited); 33: * Contributor(s): -; 34: * 35: * Changes: 36: * -------- 37: * 05-Feb-2002 : Version 1 (DG); 38: * 05-Feb-2005 : Added equals() method and implemented Serializable (DG); 39: * 02-Oct-2007 : Added getMeanValue() and getStandardDeviationValue() methods 40: * for convenience, and toString() method for debugging (DG); 41: * 42: */ 43: 44: package org.jfree.data.statistics; 45: 46: import java.io.Serializable; 47: 48: import org.jfree.util.ObjectUtilities; 49: 50: /** 51: * A simple data structure that holds a mean value and a standard deviation 52: * value. This is used in the 53: * {@link org.jfree.data.statistics.DefaultStatisticalCategoryDataset} class. 54: */ 55: public class MeanAndStandardDeviation implements Serializable { 56: 57: /** For serialization. */ 58: private static final long serialVersionUID = 7413468697315721515L; 59: 60: /** The mean. */ 61: private Number mean; 62: 63: /** The standard deviation. */ 64: private Number standardDeviation; 65: 66: /** 67: * Creates a new mean and standard deviation record. 68: * 69: * @param mean the mean. 70: * @param standardDeviation the standard deviation. 71: */ 72: public MeanAndStandardDeviation(double mean, double standardDeviation) { 73: this(new Double(mean), new Double(standardDeviation)); 74: } 75: 76: /** 77: * Creates a new mean and standard deviation record. 78: * 79: * @param mean the mean (<code>null</code> permitted). 80: * @param standardDeviation the standard deviation (<code>null</code> 81: * permitted. 82: */ 83: public MeanAndStandardDeviation(Number mean, Number standardDeviation) { 84: this.mean = mean; 85: this.standardDeviation = standardDeviation; 86: } 87: 88: /** 89: * Returns the mean. 90: * 91: * @return The mean. 92: */ 93: public Number getMean() { 94: return this.mean; 95: } 96: 97: /** 98: * Returns the mean as a double primitive. If the underlying mean is 99: * <code>null</code>, this method will return <code>Double.NaN</code>. 100: * 101: * @return The mean. 102: * 103: * @see #getMean() 104: * 105: * @since 1.0.7 106: */ 107: public double getMeanValue() { 108: double result = Double.NaN; 109: if (this.mean != null) { 110: result = this.mean.doubleValue(); 111: } 112: return result; 113: } 114: 115: /** 116: * Returns the standard deviation. 117: * 118: * @return The standard deviation. 119: */ 120: public Number getStandardDeviation() { 121: return this.standardDeviation; 122: } 123: 124: /** 125: * Returns the standard deviation as a double primitive. If the underlying 126: * standard deviation is <code>null</code>, this method will return 127: * <code>Double.NaN</code>. 128: * 129: * @return The standard deviation. 130: * 131: * @since 1.0.7 132: */ 133: public double getStandardDeviationValue() { 134: double result = Double.NaN; 135: if (this.standardDeviation != null) { 136: result = this.standardDeviation.doubleValue(); 137: } 138: return result; 139: } 140: 141: /** 142: * Tests this instance for equality with an arbitrary object. 143: * 144: * @param obj the object (<code>null</code> permitted). 145: * 146: * @return A boolean. 147: */ 148: public boolean equals(Object obj) { 149: if (obj == this) { 150: return true; 151: } 152: if (!(obj instanceof MeanAndStandardDeviation)) { 153: return false; 154: } 155: MeanAndStandardDeviation that = (MeanAndStandardDeviation) obj; 156: if (!ObjectUtilities.equal(this.mean, that.mean)) { 157: return false; 158: } 159: if (!ObjectUtilities.equal( 160: this.standardDeviation, that.standardDeviation) 161: ) { 162: return false; 163: } 164: return true; 165: } 166: 167: /** 168: * Returns a string representing this instance. 169: * 170: * @return A string. 171: * 172: * @since 1.0.7 173: */ 174: public String toString() { 175: return "[" + this.mean + ", " + this.standardDeviation + "]"; 176: } 177: 178: }