tweag / random-quality

Framework for testing quality of random number generators

random-quality

There are many now quite venerable and newer test suites that will check the quality of random number generators but none of them are particularly easy to install and use:

• dieharder
• TestU01 (SmallCrush, Crush, BigCrush)
• PractRand
• gjrand
• rademacher-fpl

This repo provides a nix-shell which will build dieharder, TestU01 and PractRand and allow you (in the nix shell) to use them almost all identically with the minimum amount of fuss.

Optionally, this repo contains a Haskell program that will generate a stream of random numbers from some of the Haskell random number generator implementations. See generate/README.md for details.

Setup

• Enter the test environment containing only the PRNG test batteries:

  nix-shell https://github.com/tweag/random-quality/archive/master.tar.gz

  To test that the environment is set up correctly, run:

  RNG_test stdin32 < /dev/zero

  This should show a spectacularly failed test: /dev/zero is not a good PRNG. See Tests for details.

• Alternatively, enter the test environment containing the PRNG test batteries as well as a number of Haskell PRNGs:

  nix-shell https://github.com/tweag/random-quality/archive/master.tar.gz \
      --arg buildHaskell true

  To test that the environment is set up correctly, run:

  generate random-word32 | RNG_test stdin32

  The whole test takes a long time, you can cancel it with Ctrl+C. This uses the random library to generate a sequence of random numbers. See Generators and Tests for details.

Tests

The following randomness test suites are available in the repository via Nix, all of which accept a stream of random numbers on stdin:

• dieharder: run dieharder -a -g200 to execute all available tests (-a). See dieharder -h for more options.
• PractRand: run via RNG_test stdin32 to test a stream of 32-bit random numbers. See RNG_test -help for details.
• TestU01: run via TestU01_stdin -[s|c|b], which expects a stream of 32-bit random numbers. Three test batteries are available: -s starts SmallCrush, -c starts Crush, -b starts BigCrush.
• gjrand: run via pmcp to execute the standard test size (1 GB) on ints, and pmcpf to test double precision floating point numbers. See pmcp -h and pmcpf -h for options.
• rademacher-fpl: run via detect-significand-bias to execute the standard test size (10 MB) on double precision floating point numbers.