From: Yann Duplouy <yann.duplouy@inria.fr>
Date: Mon, 21 Oct 2019 09:42:49 +0000 (+0200)
Subject: Adding the normal distribution
X-Git-Tag: v3.25~386^2~8
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/af116ea50535b17960c8c7d963fe9485787b2651

Adding the normal distribution
---

diff --git a/src/xbt/random.cpp b/src/xbt/random.cpp
index 7f8af6affb..b0f172a290 100644
--- a/src/xbt/random.cpp
+++ b/src/xbt/random.cpp
@@ -51,7 +51,12 @@ double normal(double mean, double sd)
   unsigned long numeratorA = mt19937_gen() - mt19937_gen.min();
   unsigned long numeratorB = mt19937_gen() - mt19937_gen.min();
   unsigned long divisor    = mt19937_gen.max() - mt19937_gen.min();
-  double z0                = sqrt(-2.0 * log(numeratorA / divisor)) * cos(2 * M_PI * numeratorB / divisor);
+  double u1                = numeratorA / divisor;
+  while (u1 < DBL_MIN) {
+    numeratorA = mt19937_gen() - mt19937_gen.min();
+    u1         = numeratorA / divisor;
+  }
+  double z0 = sqrt(-2.0 * log(numeratorA / divisor)) * cos(2 * M_PI * numeratorB / divisor);
   return z0 * sd + mean;
 }