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Annotation of OpenXM_contrib/PHC/Ada/Math_Lib/Numbers/standard_random_numbers.adb, Revision 1.1

1.1     ! maekawa     1: with Machines;                           use Machines;
        !             2: with Standard_Mathematical_Functions;    use Standard_Mathematical_Functions;
        !             3:
        !             4: package body Standard_Random_Numbers is
        !             5:
        !             6:   a : constant integer := 13849;
        !             7:   m : constant integer := 65536;
        !             8:   c : constant integer := 56963;
        !             9:   seed : integer := Process_Id;
        !            10:
        !            11:   function Random ( lower,upper : integer ) return integer is
        !            12:
        !            13:     f : double_float;
        !            14:
        !            15:   begin
        !            16:     f := Random; -- f in [-1,1]
        !            17:     f := 0.5*(double_float(upper-lower)*f + double_float(lower+upper));
        !            18:                                          -- f in [lower,upper]
        !            19:     return integer(f); -- rounding the result to integer number
        !            20:   end Random;
        !            21:
        !            22:   function Random return double_float is
        !            23:
        !            24:     x : double_float;
        !            25:
        !            26:   begin
        !            27:     seed := (a*seed + c) mod m;
        !            28:     x := double_float(seed)/double_float(m);
        !            29:     x := 2.0 * x - 1.0;
        !            30:     return x;
        !            31:   end Random;
        !            32:
        !            33:   function Random return Complex_Number is
        !            34:   begin
        !            35:     return Create(Random,Random);
        !            36:   end Random;
        !            37:
        !            38:   function Random ( modulus : double_float ) return Complex_Number is
        !            39:
        !            40:     arg : double_float;
        !            41:
        !            42:   begin
        !            43:     arg := PI*Random;  -- in [-pi,+pi]
        !            44:     return Create(modulus*COS(arg),modulus*SIN(arg));
        !            45:   end Random;
        !            46:
        !            47:   function Random1 return Complex_Number is
        !            48:
        !            49:     arg : double_float;
        !            50:
        !            51:   begin
        !            52:     arg := PI*Random;  -- in [-pi,+pi]
        !            53:     return Create(COS(arg),SIN(arg));
        !            54:   end Random1;
        !            55:
        !            56: end Standard_Random_Numbers;