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  • Committer: edA-qa mort-ora-y
  • Date: 2010-02-16 05:36:32 UTC
  • Revision ID: eda-qa@disemia.com-20100216053632-60lt7fndfi3fgblw
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lib/mathx/LinearCongruentialGenerator.hx
 
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/* <license>
 
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 * This file is part of the dis-Emi-A HaXe Library. Copyright © edA-qa mort-ora-y
 
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 * For full copyright and license information please refer to doc/license.txt.
 
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 * </license> 
 
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 */
 
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package mathx;
 
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/**
 
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 * The classic random number generator.
 
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 * http://en.wikipedia.org/wiki/Linear_congruential_generator
 
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 */
 
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class LinearCongruentialGenerator implements RandomGenerator
 
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{
 
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        var a : Int;
 
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        var c : Int;
 
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        var cur : Int;
 
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        public function new( a : Int, c : Int, ?seed : Null<Int> = null )
 
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        {
 
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                this.a = a;
 
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                this.c = c;
 
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                if( seed == null )
 
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                        cur = Math.round( haxe.Timer.stamp() * 1000 );
 
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                else
 
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                        cur = seed;
 
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        }
 
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        static public function standard() 
 
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        {
 
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#if neko
 
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                //from Numeric recipes
 
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                return new LinearCongruentialGenerator( 1664525, 1013904223 );
 
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#else
 
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                //from GCC
 
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                return new LinearCongruentialGenerator( 1103515245, 12345 );
 
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#end
 
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        }
 
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        public function nextFloat() : Float
 
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        {
 
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                return nextInt() / Limits.intMax;
 
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        }
 
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        public function nextInt() : Int
 
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        {
 
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                cur = cur * a + c;
 
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                return MathUtil.absi( cur );
 
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        }
 
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        public function reseed( seed : Int ) : Void
 
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        {
 
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                cur = seed;
 
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        }
 
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}