PCGRandom

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Ruby wrappers for the PCG (Permuted LCG) family of random number generators.

Installation

Prerequisites

• A C-compiler (any modern C compiler is supported on *nix, Windows isn't supported yet)
• Modified C source code for pcg_random available here for building libpcg_random.
• Follow the build instructions given here to build libpcg_random

Installing the gem:

• Rubygems:

gem install pcg_random

You can also configure the path to libpcg_random by specifying it's path explicitly:

# specify the custome include path
gem install pcg_random --with-pcg_random-include=directory/containing/pcg_variants.h

# or, specify the custom path to the libpcg_random binary
gem install pcg_random --with-pcg_random-lib=directory/containing/libpcg_random.a

# Or, specify both the lib/ and include/ together to be under path/to/some/directory
gem install pcg_random --with-pcg_random-dir=path/to/some/directory

Development

TODO: Create a CONTRIBTING.md

Install pcg_random from source using the above steps. Using the above links are important because the library must be compiled with additional flags to be used for gem-development. There are also some issues in the original repository that are addressed in my fork.

Using the extension

Either jump into your REPL of choice:

~$ irb
2.3.0 :001 > require 'pcg_random'
 => true

Go ahead and try it, it's built to be as close to Kernel::Random as possible!

2.3.0 :002 > seed = PCGRanom.new_seed
 => 315431527813695542666700950080169144774
2.3.0 :003 > rng = PCGRanom.new 1234
 => #<PCGRandom:0x000000022bdf70 @seed=1234>
2.3.0 :004 > rng.rand
 => 0.48717727651819587
2.3.0 :005 > rng.rand 1.618
 => 1.0251792164160871
2.3.0 :006 > rng.rand 189
 => 184
2.3.0 :007 > rng.rand 64499150491713080311265783184370031348
 => 23781278266665729678291694765199065088

For detailed instructions, have a look at the glorious wiki (Work In Progress™)

Benchmarks

See wiki benchmark section for detailed benchmarks

Roadmap

• Achieve parity with Kernel::Random
• Make a wiki explaining how to go about using this gem
  • Guide to install libpcg_random
  • New contributor's / beginners guide
  • Sample programs
  • Benchmarks vs Kernel::Random