Changeset 425 for trunk/lib/random/random.h

Timestamp:

Dec 7, 2005, 3:14:24 PM (16 years ago)

Author:

Jari Häkkinen

Message:

Fixed bug in DiscreteUniform?.
Added seeding support for classes derived from Discrete and Continuous
virtual classes.

File:

• trunk/lib/random/random.h (modified) (7 diffs)

trunk/lib/random/random.h

@@ -47 +47 @@
   /// documentation.
   ///
-  /// @todo Is this class properly implemented? The underlying random
-  /// number genereator should be a singleton, while allowing for
-  /// several different distribution to be used. Jari's feeling is
-  /// that the current implementation restricts the use to only one
-  /// distribution per binary!
+  /// @todo Get those exceptions in! Should classes be considered
+  /// const if underlying structures are changed such as GSL stuff?
   ///
   class RNG
@@ -60 +57 @@
 
     ///
-    /// @brief Get an instance of the random number
-    /// generator/distribution.
+    /// Get an instance of the random number generator. If the random
+    /// number generator is not already created, the call will create
+    /// a new generator and use the default seed. I needed, the seed
+    /// must be changed with the seed or seed_from_devurandom member
+    /// functions.
+    ///
+    /// @brief Get an instance of the random number generator.
     ///
     /// @return A pointer to the random number generator.
     ///
-    static RNG* instance(u_long seed=0)
-      { if (!instance_) instance_=new RNG(seed); return instance_; }
+    /// @see seed and seed_from_devurandom
+    ///
+    static RNG* instance(void)
+      { if (!instance_) instance_=new RNG; return instance_; }
 
     ///
@@ -106 +110 @@
 
   private:
-    RNG(u_long seed);
+    RNG(void);
 
     static RNG* instance_;
@@ -122 +126 @@
   /// with its probability.
   ///
-  class Discrete 
+  class Discrete
   {
   public:
@@ -129 +133 @@
     ///
     inline Discrete(void) { rng_=RNG::instance(); }
+
+    ///
+    /// Set the seed to \a s in the underlying rng. If \a s is zero, a
+    /// default value from the rng's original implementation is used
+    /// (cf. GSL documentation).
+    ///
+    /// @brief Set the seed to \a s.
+    ///
+    /// @see seed_from_devurandom, RNG::seed_from_devurandom, RNG::seed
+    ///
+    inline void seed(u_long s) const { rng_->seed(s); }
+
+    ///
+    /// @brief Set the seed using the /dev/urandom device.
+    ///
+    /// @return The seed acquired from /dev/urandom.
+    ///
+    /// @see seed, RNG::seed_from_devurandom, RNG::seed
+    ///
+    u_long seed_from_devurandom(void) { return rng_->seed_from_devurandom(); }
 
     ///
@@ -190 +214 @@
     /// @brief Default constructor.
     ///
-    DiscreteUniform(void) : range_(rng_->max()+1) {}
+    DiscreteUniform(void) : range_(rng_->max()) {}
 
     ///
     /// @brief Constructor.
     ///
-    /// @param n sets the range. Object will generate integers from
-    /// [0,n-1].
+    /// The generator will generate integers from \f$ [0,n-1] \f$. If
+    /// \a n is larger than the maximum number the random number
+    /// generator can return, then (currently) \a n is adjusted
+    /// appropriately.
+    ///
+    /// @todo If a too large \a n is given an exception should be
+    /// thrown, i.e. the behaviour of this class will change. The case
+    /// when argument is 0 is not treated gracefully (underlying GSL
+    /// functionality will not return).
     ///
     DiscreteUniform(const u_long n) : range_(n)
-    { if ( range_-1>rng_->max() ) range_=rng_->max()+1; }
+    { if ( range_>rng_->max() ) range_=rng_->max(); }
 
     ///
@@ -281 +312 @@
 
     ///
+    /// Set the seed to \a s in the underlying rng. If \a s is zero, a
+    /// default value from the rng's original implementation is used
+    /// (cf. GSL documentation).
+    ///
+    /// @brief Set the seed to \a s.
+    ///
+    /// @see seed_from_devurandom, RNG::seed_from_devurandom, RNG::seed
+    ///
+    inline void seed(u_long s) const { rng_->seed(s); }
+
+    ///
+    /// @brief Set the seed using the /dev/urandom device.
+    ///
+    /// @return The seed acquired from /dev/urandom.
+    ///
+    /// @see seed, RNG::seed_from_devurandom, RNG::seed
+    ///
+    u_long seed_from_devurandom(void) { return rng_->seed_from_devurandom(); }
+
+    ///
     /// @return A random number
     ///