Source code: org/mrd/jelly/random/Gamma.java
1 /*
2 * Copyright (C) 2002-2003, Mark Diggory
3 *
4 * This file is part of the Repast Taglibrary Package for use with Jelly.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. License
19 * information is also available at http://www.gnu.org.
20 *
21 * @author Mark Diggory <mdiggory@latte.harvard.edu>
22 */
23
24 package org.mrd.jelly.random;
25
26 import org.apache.commons.jelly.*;
27
28 /** This is a random number generation class that produces pseudo-random
29 * doubles acording to a configured Lambda Distribution. The Distribution is
30 * supported by the cern.jet.random.Gamma Distribution Class.
31 *
32 * The distribution can be configured by two strategies
33 *
34 * 1.) Alpha and Lambda parameters can be provided for the distribution.
35 *
36 *
37 * @author Mark R. Diggory
38 */
39 public class Gamma extends DistributionTagBase {
40
41 /** Holds value of property alpha. */
42 private double alpha;
43
44 /** Holds value of property lambda. */
45 private double lambda;
46
47 /** Used by Ant to check if the appropriate attributes have been filled out.
48 * @throws BuildException if attribute is not correctly filled in.
49 */
50 public void doStartTag(XMLOutput xMLOutput)
51 throws MissingAttributeException,
52 JellyTagException {
53
54
55 if (getVar() == null)
56 throw new MissingAttributeException("var");
57
58 if(!(alpha > Double.MIN_VALUE))
59 throw new MissingAttributeException("alpha");
60
61 if(!(lambda > Double.MIN_VALUE))
62 throw new MissingAttributeException("lambda");
63
64 context.setVariable(getVar(),new cern.jet.random.Gamma(alpha, lambda,this.getRandomElement()));
65
66 }
67
68
69 /** Getter for property alpha.
70 * @return Value of property alpha.
71 */
72 public double getAlpha() {
73 return alpha;
74 }
75
76 /** Setter for property alpha.
77 * @param alpha New value of property alpha.
78 */
79 public void setAlpha(double alpha) {
80 this.alpha = alpha;
81 }
82
83 /** Getter for property lambda.
84 * @return Value of property lambda.
85 */
86 public double getLambda() {
87 return lambda;
88 }
89
90 /** Setter for property lambda.
91 * @param lambda New value of property lambda.
92 */
93 public void setLambda(double lambda) {
94 this.lambda = lambda;
95 }
96
97 }