Changeset 3099 in Sophya for trunk/SophyaLib/BaseTools/srandgen.c

Timestamp:

Nov 2, 2006, 3:37:05 PM (19 years ago)

Author:

ansari

Message:

Ajout PoissRand() + classe RandomGenerator / doc ds srandgen.h .cc , Reza 02/11/2006

File:

• trunk/SophyaLib/BaseTools/srandgen.c (modified) (3 diffs)

trunk/SophyaLib/BaseTools/srandgen.c

@@ -243 +243 @@
 }
 
+/*! \ingroup  BaseTools
+  \brief Poisson random number generator.
+  
+  Return an integer value (>=0) corresponding a Poisson distribution with mean \b mu.
+  \warning NOT the most efficient way of generating a large series of numbers
+  with the SAME mean
+*/
+int PoissRand(double mu)
+{
+  double pp,ppi;
+  ppi = pp = exp(-mu);
+  double x = drand01();
+  int n = 0;
+  while (x > ppi) {
+    n++;
+    pp = mu*pp/(double)n;
+    ppi += pp;
+  }
+  return n;
+}
+
 /*=========================================================================*/
 /*
@@ -250 +271 @@
         sigma "s" la distribution est limitee entre am +/- GAU_RANGE (obsolete).
 --
+*/
+/*! \ingroup  BaseTools
+ \brief OBSOLETE (gaussian random number generator)
 */
 double GauRnd1(double am, double s)
@@ -371 +395 @@
 }
 
+
+/*! 
+  \ingroup  BaseTools
+  \class SOPHYA::RandomGenerator
+  \brief Random number generator
+  
+  This is a class with static methods, providing an alternative interface 
+  to random number generations functions declared in srandgen.h.
+
+  \sa frand01 drand01 frandpm1 drandpm1 
+  \sa GauRnd PoissRand
+  \sa Ini_Ranf_Quick Ini_Ranf Get_Ranf Auto_Ini_Ranf
+*/
+
 /*==========================================================================*/
 /*