The mwc-random package

[Tags: bsd3, library]

Fast, high quality pseudo random numbers.

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Change logNone available
Dependenciesbase (<5), time, uvector (>= [details]
Copyright2009 Bryan O'Sullivan
AuthorBryan O'Sullivan <>
MaintainerBryan O'Sullivan <>
CategoryMath, Statistics
Home page
UploadedSat Dec 26 05:56:01 UTC 2009 by BryanOSullivan
DistributionsDebian:, Fedora:, FreeBSD:, LTSHaskell:, NixOS:, Stackage:
Downloads61084 total (165 in last 30 days)
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StatusDocs uploaded by user
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Maintainers' corner

For package maintainers and hackage trustees

Readme for mwc-random-0.4.1

Efficient, general purpose pseudo-random number generation

This package provides the System.Random.MWC module, a Haskell library
for generating high-quality pseudo-random numbers in a space- and
time-efficient way.


This library has been carefully optimised for high performance.  To
obtain the best runtime efficiency, it is imperative to compile
libraries and applications that use this library using a high level of

Suggested GHC options:

  -O -fvia-C -funbox-strict-fields

To illustrate, here are the times (in seconds) to generate and sum 250
million random Word32 values, on a laptop with a 2.4GHz Core2 Duo
P8600 processor, running Fedora 11 and GHC 6.10.3:

  no flags   200+
  -O           1.249
  -O -fvia-C   0.991

As the numbers above suggest, compiling without optimisation will
yield unacceptable performance.

Get involved!

Please feel welcome to contribute new code or bug fixes.  You can
fetch the source repository from here:

darcs get


Bryan O'Sullivan <>