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sample-random-variable.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 as
5  * published by the Free Software Foundation;
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * along with this program; if not, write to the Free Software
14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15  */
16 #include "ns3/simulator.h"
17 #include "ns3/nstime.h"
18 #include "ns3/command-line.h"
19 #include "ns3/random-variable.h"
20 #include <iostream>
21 
22 using namespace ns3;
23 
24 /*
25  * This program can be run from waf such as "./waf --run sample-random-variable"
26  *
27  * This program is about as simple as possible to display the use of ns-3
28  * to generate random numbers. By default, the uniform random variate that
29  * will be outputted is 0.816532. Because ns-3 uses a fixed seed for the
30  * pseudo-random number generator, this program should always output the
31  * same number. Likewise, ns-3 simulations using random variables will
32  * behave deterministically unless the user changes the RunNumber or the
33  * Seed.
34  *
35  * There are three primary mechanisms to change the seed or run numbers
36  * from their default integer value of 1
37  * 1) Through explicit call of SeedManager::SetSeed () and
38  * SeedManager::SetRun () (commented out below)
39  * 2) Through the passing of command line arguments such as:
40  * "./waf --command-template="%s --RngRun=<value>" --run program-name"
41  * 3) Through the use of the NS_GLOBAL_VALUE environment variable, such as:
42  * "NS_GLOBAL_VALUE="RngRun=<value>" ./waf --run program-name"
43  *
44  * For instance, setting the run number to 3 will change the program output to
45  * 0.775417
46  *
47  * Consult the ns-3 manual for more information about the use of the
48  * random number generator
49  */
50 
51 int main (int argc, char *argv[])
52 {
53  CommandLine cmd;
54  cmd.Parse (argc, argv);
55 
56  // SeedManager::SetRun (3);
57 
58  UniformVariable uv;
59 
60  std::cout << uv.GetValue () << std::endl;
61 
62 }
double GetValue(void) const
call RandomVariable::GetValue
The uniform distribution RNG for NS-3.
Parse command-line arguments.
Definition: command-line.h:177
void Parse(int argc, char *argv[])
Parse the program arguments.
int main(int argc, char *argv[])