Changeset 3838 in Sophya for trunk/SophyaLib/BaseTools/randr48.cc

Timestamp:

Aug 9, 2010, 7:31:12 PM (15 years ago)

Author:

ansari

Message:

MAJ commentaires pour doxygen, passage methode Next() en pure virtual (=0), Reza 09/08/2010

File:

• trunk/SophyaLib/BaseTools/randr48.cc (modified) (2 diffs)

trunk/SophyaLib/BaseTools/randr48.cc

@@ -10 +10 @@
 namespace SOPHYA {
 
+/*!
+   \class DR48RandGen
+   \ingroup BaseTools
+   \brief  Implementation of the RandomGeneratorInterface class using drand48() functions 
+
+   Its PPF handler can be used to save the complete state of the class and the underlying
+   random number generator used.
+
+   \sa SOPHYA::ObjFileIO<ThSDR48RandGen>
+
+*/
+
 static bool dr48_first = true;
 DR48RandGen::DR48RandGen()
@@ -70 +82 @@
    \class ThSDR48RandGen
    \ingroup BaseTools
-   \brief Random number generator
-
-   This class is a thread-safe random number generator.
+   \brief Thread-safe version of DR48RandGen random number generator using drand48() functions.
+
+   
+   Several instances of this class can be used in different threads without the risk of 
+   corrupting the internal state of the drand48() generator. However, in multi-thread applications,
+   there is no guarantee to obtain the same sequence of numbers in each thread.  
    Its PPF handler can be used to save the complete state of the class and the underlying
-   random number generator used.
+   random number generator (drand48() which is used.
 
    \sa SOPHYA::ObjFileIO<ThSDR48RandGen>
 
+   \code 
+   // A.1- Create a thread safe generator based on drand48() 
+   ThSDR48RandGen rg;
+   // A.2- Auto initilize its state (using the system time) 
+   rg.AutoInit();
+   // A.3- compute and print a smal sequence of random numbers 
+   int N = 10;
+   for(int i=0; i<N; i++) 
+     cout << " I=" << i << "  rand_flat01= " << rg.Flat01() << " rand.gaussian= " << rg.Gaussian() << endl;
+   // A.4- Save the generator state for subsequent use
+   POutPersist po("rg.ppf");
+   po << rg;
+   // A.5- compute and print a second sequence of random numbers 
+   for(int i=0; i<N; i++) 
+     cout << "++ I=" << i+N << "  rand_flat01= " << rg.Flat01() << " rand.gaussian= " << rg.Gaussian() << endl;
+   
+   ...  In another program :
+
+   // B.1- Create and initialize the generator from the previously saved state
+   ThSDR48RandGen rgr;
+   PInPersist pin("rg.ppf");
+   pin >> rgr;
+   int N = 10;
+   // B.2- Compute and print a sequence of random number, should be compared to the sequance A.5
+   for(int i=0; i<N; i++) 
+     cout << "-- I=" << i << "  rand_flat01= " << rgr.Flat01() << " rand.gaussian= " << rgr.Gaussian() << endl;
+   
+   
+   \endcode
 */
 
 // Objet statique global pour gestion de lock entre threads
 static ThSafeOp* ths_rand = NULL;
+
+/*! 
+  \brief Constructor with optional specification of the internal buffer size and thread-safety flag 
+  
+  The behaviour of the base class DR48RandGen can be reproduced by specifying tsafe=false
+  \param n : an internal buffer of size n is created and filled through block calls to drand48()
+  \param tsafe : if false, creates a non thread-safe generator 
+*/
 
 ThSDR48RandGen::ThSDR48RandGen(size_t n, bool tsafe)