xorshift (empty) → 1
raw patch · 4 files changed
+683/−0 lines, 4 filessetup-changed
Files
- COPYING +481/−0
- Setup.lhs +6/−0
- src/Random/Xorshift.hs +154/−0
- xorshift.cabal +42/−0
+ COPYING view
@@ -0,0 +1,481 @@+ GNU LIBRARY GENERAL PUBLIC LICENSE+ Version 2, June 1991++ Copyright (C) 1991 Free Software Foundation, Inc.+ 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++[This is the first released version of the library GPL. It is+ numbered 2 because it goes with version 2 of the ordinary GPL.]++ Preamble++ The licenses for most software are designed to take away your+freedom to share and change it. By contrast, the GNU General Public+Licenses are intended to guarantee your freedom to share and change+free software--to make sure the software is free for all its users.++ This license, the Library General Public License, applies to some+specially designated Free Software Foundation software, and to any+other libraries whose authors decide to use it. 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+ Setup.lhs view
@@ -0,0 +1,6 @@+#!/usr/bin/runhaskell +> module Main where+> import Distribution.Simple+> main :: IO ()+> main = defaultMain+
+ src/Random/Xorshift.hs view
@@ -0,0 +1,154 @@+-----------------------------------------------------------------------------+--+-- Module : Random.Xorshift+-- Copyright :+-- License : LGPL 2.0 or higher+--+-- Maintainer :+-- Stability :+-- Portability :+--+-- | Xorshift random generators. The generators are implemented according to+-- the paper <http://www.jstatsoft.org/v08/i14/paper> by George Marsaglia.+-- You can use the 'RandomGen' instances to generate random numbers easily.+-----------------------------------------------------------------------------++{-# LANGUAGE GeneralizedNewtypeDeriving, CPP #-}++-- Use the C-header file to generate a platform depend Xorshift type+-- This is handy as I can use the __Xorshift macro as a data-constructor.+#include "MachDeps.h"+#if WORD_SIZE_IN_BITS == 32+#define __Xorshift Xorshift32+#else+#define __Xorshift Xorshift64+#endif++module Random.Xorshift (+ Xorshift32 (..),+ Xorshift64 (..),+ Xorshift,+ newXorshift32,+ newXorshift64,+ newXorshift,+ makeXorshift32,+ makeXorshift64,+ makeXorshift,+ getInt64,+ getInt32,+ module System.Random+ ) where++import Data.Int (Int32,Int64)+import Data.Bits (xor,shiftL,shiftR)+import System.Random+import Data.Time++-- | Xorshift generator with 32 bits.+-- This Xorshift generator uses first a left shift, then a right shift and+-- again a left shift. It uses the parameters 13, 17 and 5. See the paper for+-- more details on how the parameters affect the generation of random numbers.+--+-- The generator has a periode of 2^32-1, please notice that the+-- generator has to be initialized with a value different from 0, elseway all+-- future values will be zero as well.+newtype Xorshift32 = Xorshift32 Int32+ deriving (Eq,Show,Enum,Bounded)++-- | Xorshift generator with 64 bits.+-- This Xorshift generator uses first a left shift, then a right shift and+-- again a left shift. It uses the parameters 13, 7 and 17. See the paper for+-- more details on how the parameters affect the generation of random numbers.+--+-- The generator has a periode of 2^64-1, please notice that the+-- generator has to be initialized with a value different from 0, elseway all+-- future values will be zero as well.+newtype Xorshift64 = Xorshift64 Int64+ deriving (Eq,Show,Enum,Bounded)++-- | Generates a new Xorshift32 from the current time.+newXorshift32 :: IO Xorshift32+newXorshift32 = getRandomValue >>= return . makeXorshift32++-- | Generates a new Xorshift32 from the current time.+newXorshift64 :: IO Xorshift64+newXorshift64 = getRandomValue >>= return . makeXorshift64++-- | Generates a new Xorshift from the current time. This is either a synonym+-- for 'newXorshift32' or 'newXorshift64'.+newXorshift :: IO Xorshift+newXorshift = getRandomValue >>= return . makeXorshift++-- | Generate a new 'Xorshift32' generator. This is essentially a wrapper around+-- the constructor.+makeXorshift32 :: Integral a => a -> Xorshift32+makeXorshift32 = Xorshift32 . fromIntegral++-- | Generate a new 'Xorshift64' generator. This is essentially a wrapper around+-- the constructor.+makeXorshift64 :: Integral a => a -> Xorshift64+makeXorshift64 = Xorshift64 . fromIntegral++-- | Generate a new 'Xorshift' generator, regardless of whatever it's bytesize+-- is on your platform.+makeXorshift :: Integral a => a -> Xorshift+makeXorshift = __Xorshift . fromIntegral++-- | Get the raw contents of the random generator. This function is preferable+-- over direct usage of the constructor itself, as the internal representation+-- of the random generator may change in future releases.+--+-- The 'getInt32' function works for 'Xorshift32' and the 'getInt64' function+-- works for 'Xorshift64'. If you're using the 'Xorshift' type, use an 'Int'+-- type in combination with the 'random' methof of "System.Random".+getInt32 :: Xorshift32 -> Int32+getInt32 (Xorshift32 a) = a++getInt64 :: Xorshift32 -> Int32+getInt64 (Xorshift32 a) = a++instance RandomGen Xorshift32 where+ next a = (fromIntegral c, b) where+ b@(Xorshift32 c) = step32 a+ split = error "Splitting of an Xorshift random generator is not implemented."+ genRange a = (fromEnum (minBound `asTypeOf` a),+ fromEnum (maxBound `asTypeOf` a))++instance RandomGen Xorshift64 where+ next a = (fromIntegral c, b) where+ b@(Xorshift64 c) = step64 a+ split = error "Splitting of an Xorshift random generator is not implemented."+ genRange a = (fromEnum (minBound `asTypeOf` a),+ fromEnum (maxBound `asTypeOf` a))++-- | The type Xorshift is a wrapper around either 'Xorshift32' or 'Xorshift64',+-- depending on the bit size of your system. The idea behind this is, that you+-- may want to use this package as an uncomplicated, fast random generator,+-- but repeated conversion between different word sizes are an absolute+-- performance killer.+--+-- Thus, if you don't really care about the period of your random generator or+-- how long the result is, use the 'Xorshift' synonym, whenever possible.+type Xorshift = __Xorshift++-- Iterates the random generator for 32 bits+step32 :: Xorshift32 -> Xorshift32+step32 (Xorshift32 a) = Xorshift32 d where+ b = a `xor` (shiftL a 13)+ c = b `xor` (shiftR b 17)+ d = c `xor` (shiftL c 5)++-- Iterates the random generator for 64 bits+step64 :: Xorshift64 -> Xorshift64+step64 (Xorshift64 a) = Xorshift64 d where+ b = a `xor` (shiftL a 13)+ c = b `xor` (shiftR b 7)+ d = c `xor` (shiftL c 17)++-- Generates a random value from current time. We try to archieve a good result+-- by summing all information of time.+getRandomValue :: IO Integer+getRandomValue = do UTCTime (ModifiedJulianDay day) time <- getCurrentTime+ let picosecs = truncate $ toRational time * 10^12+ dayInPs = day * 86400 * 10^12+ return $! picosecs + dayInPs
+ xorshift.cabal view
@@ -0,0 +1,42 @@+name: xorshift+version: 1+Cabal-Version: >= 1.6+build-type: Simple++license: LGPL+copyright: ©2010 Robert Clausecker+license-file: "COPYING"++author: Robert Clausecker <fuzxxl@gmail.com>+bug-reports: http://https://github.com/fuzxxl/Xorshift/issues+maintainer: Robert Clausecker++build-depends: base -any, random -any, time -any+stability:+homepage:+package-url:+synopsis: Haskell implementation of the xorshift random generator.+description: The Xorshift random generator is a very fast generator that uses+ only XOR and bitshifting operations. This package contains a basic version+ with a periode of 2^32-1 for 32-bit numbers and a version with a periode of+ 2^64-1 for 64-bit numbers. The author didn't tested the random generator,+ but according to it's specification the resulting numbers are of good+ quality.++category: Math++library+ exposed-modules: Random.Xorshift+ exposed: True+ extensions: CPP, GeneralizedNewtypeDeriving+ hs-source-dirs: src+ buildable: True++source-repository head+ type: git + location: git://github.com/fuzxxl/Xorshift.git++source-repository this+ type: git+ location: git://github.com/fuzxxl/Xorshift.git+ tag: release-1