From 00cf8f924cb7df70a4348f058ae259f72f3f395a Mon Sep 17 00:00:00 2001
From: Tom Henderson <tomh@tomh.org>
Date: Mon, 28 Dec 2009 09:43:08 -0800
Subject: [PATCH] Add simple random variable sample

---
 samples/sample-random-variable.cc | 63 +++++++++++++++++++++++++++++++
 samples/wscript                   |  4 ++
 2 files changed, 67 insertions(+)
 create mode 100644 samples/sample-random-variable.cc

diff --git a/samples/sample-random-variable.cc b/samples/sample-random-variable.cc
new file mode 100644
index 000000000..f388e5dfd
--- /dev/null
+++ b/samples/sample-random-variable.cc
@@ -0,0 +1,63 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include "ns3/simulator.h"
+#include "ns3/nstime.h"
+#include "ns3/command-line.h"
+#include "ns3/random-variable.h"
+#include <iostream>
+
+using namespace ns3;
+using namespace std;
+
+/*
+ * This program can be run from waf such as "./waf --run sample-random-variable"
+ * 
+ * This program is about as simple as possible to display the use of ns-3 
+ * to generate random numbers.  By default, the uniform random variate that
+ * will be outputted is 0.816532.  Because ns-3 uses a fixed seed for the
+ * pseudo-random number generator, this program should always output the
+ * same number.  Likewise, ns-3 simulations using random variables will
+ * behave deterministically unless the user changes the RunNumber or the
+ * Seed.  
+ * 
+ * There are three primary mechanisms to change the seed or run numbers
+ * from their default integer value of 1
+ * 1) Through explicit call of SeedManager::SetSeed () and 
+ *    SeedManager::SetRun () (commented out below) 
+ * 2) Through the passing of command line arguments such as:
+ *    "./waf --command-template="%s --RngRun=<value>" --run program-name"
+ * 3) Through the use of the NS_GLOBAL_VALUE environment variable, such as:
+ *    "NS_GLOBAL_VALUE="RngRun=<value>" ./waf --run program-name"
+ * 
+ * For instance, setting the run number to 3 will change the program output to
+ * 0.775417
+ * 
+ * Consult the ns-3 manual for more information about the use of the 
+ * random number generator
+ */
+
+int main (int argc, char *argv[])
+{
+  CommandLine cmd;
+  cmd.Parse (argc, argv);
+
+  // SeedManager::SetRun (3);
+
+  UniformVariable uv;
+
+  cout << uv.GetValue () << endl;
+  
+}
diff --git a/samples/wscript b/samples/wscript
index d9cea73a6..0d32f375c 100644
--- a/samples/wscript
+++ b/samples/wscript
@@ -54,3 +54,7 @@ def build(bld):
                                  ['core', 'simulator', 'mobility', 'wifi'])
     obj.source = 'main-ns2-mob.cc'
 
+    obj = bld.create_ns3_program('sample-random-variable',
+                                 ['core', 'simulator'])
+    obj.source = 'sample-random-variable.cc'
+