From 211ac8141e2e3d2c6d63533af1f9b7d1774b0b92 Mon Sep 17 00:00:00 2001
From: Benjamin BOUVIER <bnjbouv+github@gmail.com>
Date: Fri, 7 Sep 2012 11:37:21 -0400
Subject: [PATCH] MPI Distrib exp: added exponential distribution

---
 eo/test/mpi/t-mpi-distrib-exp.cpp | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/eo/test/mpi/t-mpi-distrib-exp.cpp b/eo/test/mpi/t-mpi-distrib-exp.cpp
index 72e934e52..bfee3d9fe 100644
--- a/eo/test/mpi/t-mpi-distrib-exp.cpp
+++ b/eo/test/mpi/t-mpi-distrib-exp.cpp
@@ -130,6 +130,33 @@ class NormalDistribution : public Distribution
     double _stddev;
 } normalDistribution;
 
+class ExponentialDistribution : public Distribution
+{
+    public:
+
+    ExponentialDistribution() : _rng( 0 )
+    {
+        // empty
+    }
+
+    void make_parser( eoParser & parser )
+    {
+        _active = parser.createParam( false, "exponential", "Exponential distribution", '\0', "Exponential").value();
+        _mean = parser.createParam( 0.0, "exponential-mean", "Mean for the exponential distribution (0 by default), in ms.", '\0', "Exponential").value();
+    }
+
+    int next_element()
+    {
+        return std::floor( _rng.negexp( _mean ) );
+    }
+
+    protected:
+
+    eoRng _rng;
+    double _mean;
+
+} exponentialDistribution;
+
 int main( int argc, char** argv )
 {
     Node::init( argc, argv );
@@ -142,6 +169,7 @@ int main( int argc, char** argv )
     std::vector<Distribution*> distribs;
     distribs.push_back( &uniformDistribution );
     distribs.push_back( &normalDistribution );
+    distribs.push_back( &exponentialDistribution );
 
     // for each available distribution, check if activated.
     // If no distribution is activated, show an error message