001: /*
002: * Globus Toolkit Public License (GTPL)
003: *
004: * Copyright (c) 1999 University of Chicago and The University of
005: * Southern California. All Rights Reserved.
006: *
007: * 1) The "Software", below, refers to the Globus Toolkit (in either
008: * source-code, or binary form and accompanying documentation) and a
009: * "work based on the Software" means a work based on either the
010: * Software, on part of the Software, or on any derivative work of
011: * the Software under copyright law: that is, a work containing all
012: * or a portion of the Software either verbatim or with
013: * modifications. Each licensee is addressed as "you" or "Licensee."
014: *
015: * 2) The University of Southern California and the University of
016: * Chicago as Operator of Argonne National Laboratory are copyright
017: * holders in the Software. The copyright holders and their third
018: * party licensors hereby grant Licensee a royalty-free nonexclusive
019: * license, subject to the limitations stated herein and
020: * U.S. Government license rights.
021: *
022: * 3) A copy or copies of the Software may be given to others, if you
023: * meet the following conditions:
024: *
025: * a) Copies in source code must include the copyright notice and
026: * this license.
027: *
028: * b) Copies in binary form must include the copyright notice and
029: * this license in the documentation and/or other materials
030: * provided with the copy.
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032: * 4) All advertising materials, journal articles and documentation
033: * mentioning features derived from or use of the Software must
034: * display the following acknowledgement:
035: *
036: * "This product includes software developed by and/or derived from
037: * the Globus project (http://www.globus.org/)."
038: *
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041: * this clause is waived.
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043: * 5) You are encouraged to package modifications to the Software
044: * separately, as patches to the Software.
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046: * 6) You may make modifications to the Software, however, if you
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052: * a) The Software must carry prominent notices stating that you
053: * changed specified portions of the Software.
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061: * 7) You may incorporate the Software or a modified version of the
062: * Software into a commercial product, if you meet the following
063: * conditions:
064: *
065: * a) The commercial product or accompanying documentation must
066: * display the following acknowledgment:
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068: * "This product includes software developed by and/or derived
069: * from the Globus Project (http://www.globus.org/) to which the
070: * U.S. Government retains a paid-up, nonexclusive, irrevocable
071: * worldwide license to reproduce, prepare derivative works, and
072: * perform publicly and display publicly."
073: *
074: * b) The user of the commercial product must be given the following
075: * notice:
076: *
077: * "[Commercial product] was prepared, in part, as an account of
078: * work sponsored by an agency of the United States Government.
079: * Neither the United States, nor the University of Chicago, nor
080: * University of Southern California, nor any contributors to
081: * the Globus Project or Globus Toolkit nor any of their employees,
082: * makes any warranty express or implied, or assumes any legal
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084: * usefulness of any information, apparatus, product, or process
085: * disclosed, or represents that its use would not infringe
086: * privately owned rights.
087: *
088: * IN NO EVENT WILL THE UNITED STATES, THE UNIVERSITY OF CHICAGO
089: * OR THE UNIVERSITY OF SOUTHERN CALIFORNIA OR ANY CONTRIBUTORS
090: * TO THE GLOBUS PROJECT OR GLOBUS TOOLKIT BE LIABLE FOR ANY
091: * DAMAGES, INCLUDING DIRECT, INCIDENTAL, SPECIAL, OR CONSEQUENTIAL
092: * DAMAGES RESULTING FROM EXERCISE OF THIS LICENSE AGREEMENT OR
093: * THE USE OF THE [COMMERCIAL PRODUCT]."
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096: * FROM THE UNITED STATES MAY REQUIRE SOME FORM OF EXPORT CONTROL
097: * LICENSE FROM THE U.S. GOVERNMENT AND THAT FAILURE TO OBTAIN SUCH
098: * EXPORT CONTROL LICENSE MAY RESULT IN CRIMINAL LIABILITY UNDER U.S.
099: * LAWS.
100: *
101: * 9) Portions of the Software resulted from work developed under a
102: * U.S. Government contract and are subject to the following license:
103: * the Government is granted for itself and others acting on its
104: * behalf a paid-up, nonexclusive, irrevocable worldwide license in
105: * this computer software to reproduce, prepare derivative works, and
106: * perform publicly and display publicly.
107: *
108: * 10) The Software was prepared, in part, as an account of work
109: * sponsored by an agency of the United States Government. Neither
110: * the United States, nor the University of Chicago, nor The
111: * University of Southern California, nor any contributors to the
112: * Globus Project or Globus Toolkit, nor any of their employees,
113: * makes any warranty express or implied, or assumes any legal
114: * liability or responsibility for the accuracy, completeness, or
115: * usefulness of any information, apparatus, product, or process
116: * disclosed, or represents that its use would not infringe privately
117: * owned rights.
118: *
119: * 11) IN NO EVENT WILL THE UNITED STATES, THE UNIVERSITY OF CHICAGO OR
120: * THE UNIVERSITY OF SOUTHERN CALIFORNIA OR ANY CONTRIBUTORS TO THE
121: * GLOBUS PROJECT OR GLOBUS TOOLKIT BE LIABLE FOR ANY DAMAGES,
122: * INCLUDING DIRECT, INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES
123: * RESULTING FROM EXERCISE OF THIS LICENSE AGREEMENT OR THE USE OF
124: * THE SOFTWARE.
125: *
126: * END OF LICENSE
127: */
128:
129: package org.griphyn.cPlanner.common;
130:
131: import java.util.Random;
132:
133: /**
134: * A Helper class that returns the Random values
135: * using java.util.Random class. It is a singleton
136: * instance, and all functions in Pegasus call it
137: * to get the random value. The singleton ensures
138: * that the number returned is random as compared
139: * to previous values. If this is not used and one
140: * ends up doing a new Random(), all the calls effectively
141: * end up setting the same seed value, nad by extension
142: * one gets the same value. Using just one Random object
143: * we hope to bypass the problem.
144: *
145: * <p>Copyright: Copyright (c) 2002</p>
146: * <p>Company: USC/ISI</p>
147: * @author Gaurang Mehta
148: * @author Karan Vahi
149: * @version $Revision: 50 $
150: */
151:
152: public class PegRandom {
153:
154: /**
155: * The object containing the instance
156: * of the java.util.Random class.
157: */
158: private static Random mRandom;
159:
160: /**
161: * This is called only once when the
162: * class is first loaded.
163: */
164: static {
165: mRandom = new Random();
166: }
167:
168: /**
169: * Returns a double value between
170: * 0.0 and 1.0.
171: */
172: public static double nextDouble() {
173: return mRandom.nextDouble();
174: }
175:
176: /**
177: * Returns a normally distributed (gaussian) random variable between
178: * 0.0 and 1.0.
179: */
180: public static double nextGaussian() {
181: return mRandom.nextGaussian();
182: }
183:
184: /**
185: * This calls the next double function
186: * and returns an integer between the
187: * 0 and upper index.
188: */
189: public static int getInteger(int upperIndex) {
190: return getInteger(0, upperIndex);
191: }
192:
193: /**
194: * This calls the next double function
195: * and returns an integer between the
196: * lower index and upper index.
197: */
198: public static int getInteger(int lowerIndex, int upperIndex) {
199: double value = nextDouble();
200: int val = 0;
201:
202: //adding one as intValue() function
203: //truncates the value instead of
204: //rounding it off.
205: upperIndex += 1;
206: value = lowerIndex + ((upperIndex - lowerIndex) * value);
207: val = new Double(value).intValue();
208:
209: if (val == upperIndex)
210: //get the one lower value
211: val -= 1;
212:
213: return val;
214: }
215: }
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