# HG changeset patch # User deba # Date 1161081628 0 # Node ID f09b1ea5c249cadf0f8d77b00ca9a838447acf54 # Parent a28b4e0aa787e9bfbc06e2274c1b589ebd6995bb Little modification on interface and documentation diff -r a28b4e0aa787 -r f09b1ea5c249 lemon/random.h --- a/lemon/random.h Tue Oct 17 10:32:12 2006 +0000 +++ b/lemon/random.h Tue Oct 17 10:40:28 2006 +0000 @@ -422,37 +422,44 @@ /// /// The generator gives back random numbers of serveral types. To /// get a random number from a range of a floating point type you - /// can use one form of the \c operator(). If you want to get random - /// number from a the {0, 1, ..., n-1} integer range use the \c - /// operator[]. And to get random number from the whole range of an - /// integer type you can use the \c integer() or \c uinteger() - /// functions. After all you can get random bool with equal chance - /// or given probability with the \c boolean() member function. + /// can use one form of the \c operator() or the \c real() member + /// function. If you want to get random number from the {0, 1, ..., + /// n-1} integer range use the \c operator[] or the \c integer() + /// method. And to get random number from the whole range of an + /// integer type you can use the argumentless \c integer() or \c + /// uinteger() functions. After all you can get random bool with + /// equal chance of true and false or given probability of true + /// result with the \c boolean() member functions. /// ///\code - /// int a = rnd[100000]; // 0..99999 + /// // The commented code is identical to the other + /// double a = rnd(); // [0.0, 1.0) + /// // double a = rnd.real(); // [0.0, 1.0) + /// double b = rnd(100.0); // [0.0, 100.0) + /// // double b = rnd.real(100.0); // [0.0, 100.0) + /// double c = rnd(1.0, 2.0); // [1.0, 2.0) + /// // double c = rnd.real(1.0, 2.0); // [1.0, 2.0) + /// int d = rnd[100000]; // 0..99999 + /// // int d = rnd.integer(100000); // 0..99999 + /// int e = rnd[6] + 1; // 1..6 + /// // int e = rnd.integer(1, 1 + 6); // 1..6 /// int b = rnd.uinteger(); // 0 .. 2^31 - 1 /// int c = rnd.integer(); // - 2^31 .. 2^31 - 1 - /// double d = rnd(); // [0.0, 1.0) - /// double e = rnd(100.0); // [0.0, 100.0) - /// double f = rnd(1.0, 2.0); // [1.0, 2.0) /// bool g = rnd.boolean(); // P(g = true) = 0.5 /// bool h = rnd.boolean(0.8); // P(h = true) = 0.8 ///\endcode /// - /// The lemon provides a global instance of the random number generator - /// which name is \c rnd. Usually it is a good programming convenience - /// to use this global generator to get random numbers. + /// The lemon provides a global instance of the random number + /// generator which name is \ref lemon::rnd "rnd". Usually it is a + /// good programming convenience to use this global generator to get + /// random numbers. /// /// \author Balazs Dezso class Random { private: -#if WORD_BIT == 32 - typedef unsigned int Word; -#elif WORD_BIT == 64 + // architecture word typedef unsigned long Word; -#endif _random_bits::RandomCore core; @@ -486,7 +493,9 @@ /// \brief Copy constructor /// /// Copy constructor. The generated sequence will be identical to - /// the other sequence. + /// the other sequence. It can be used to save the current state + /// of the generator and later use it to generate the same + /// sequence. Random(const Random& other) { core.copyState(other.core); } @@ -494,7 +503,9 @@ /// \brief Assign operator /// /// Assign operator. The generated sequence will be identical to - /// the other sequence. + /// the other sequence. It can be used to save the current state + /// of the generator and later use it to generate the same + /// sequence. Random& operator=(const Random& other) { if (&other != this) { core.copyState(other.core); @@ -504,15 +515,38 @@ /// \brief Returns a random real number /// - /// It returns a random real number from the range [0, 1). The default - /// result type of this function is double. + /// It returns a random real number from the range [0, 1). The + /// default Number type is double. template - Number operator()() { + Number real() { return _random_bits::RealConversion::convert(core); } + double real() { + return real(); + } + + /// \brief Returns a random real number + /// + /// It returns a random real number from the range [0, b). + template + Number real(Number b) { + return real() * b; + } + + /// \brief Returns a random real number + /// + /// It returns a random real number from the range [a, b). + template + Number real(Number a, Number b) { + return real() * (b - a) + a; + } + + /// \brief Returns a random real number + /// + /// It returns a random double from the range [0, 1). double operator()() { - return operator()(); + return real(); } /// \brief Returns a random real number @@ -520,7 +554,7 @@ /// It returns a random real number from the range [0, b). template Number operator()(Number b) { - return operator()() * b; + return real() * b; } /// \brief Returns a random real number @@ -528,15 +562,31 @@ /// It returns a random real number from the range [a, b). template Number operator()(Number a, Number b) { - return operator()() * (b - a) + a; + return real() * (b - a) + a; } /// \brief Returns a random integer from a range /// - /// It returns a random integer from the range {0, 1, ..., bound - 1}. + /// It returns a random integer from the range {0, 1, ..., b - 1}. template - Number operator[](const Number& bound) { - return _random_bits::Mapping::map(core, bound); + Number integer(Number b) { + return _random_bits::Mapping::map(core, b); + } + + /// \brief Returns a random integer from a range + /// + /// It returns a random integer from the range {a, a + 1, ..., b - 1}. + template + Number integer(Number a, Number b) { + return _random_bits::Mapping::map(core, b - a) + a; + } + + /// \brief Returns a random integer from a range + /// + /// It returns a random integer from the range {0, 1, ..., b - 1}. + template + Number operator[](Number b) { + return _random_bits::Mapping::map(core, b); } /// \brief Returns a random non-negative integer @@ -586,9 +636,6 @@ }; - /// \brief Global random number generator instance - /// - /// A global mersenne twister random number generator instance extern Random rnd; }