Games::Dice::Tester - Statistical tests of random-dice-rolling programs

Various statistical tests for use with dice-rolling programs.

WHAT THIS MODULE IS NOT

A way to tell you whether your random-number generator is truly random!

EXPORT

Nothing by default; :all for everything; otherwise, any of the functions listed below.

FUNCTIONS

chi_squared

Compute the chi-squared statistic V. Usage:

my ($chi_squared, $df) = chi_squared_test(observed=>[...], expected=>[...]);

where the observed and expected arrays are the number of occurrences in each category.

As a shorthand for the common case of a fair die, you can pass a scalar for expected. The expected array will then be filled with copies of that value equal in number to the size of the observed array.

As yet another alternative, you can call

my ($chi_squared, $df) = chi_squared_test(generator=>sub { ... });

where generator, when called, returns the next ($observed, $expected) pair. When the generator returns undef, the loop stops.

Returns the chi-squared statistic. In list context, also returns the number of degrees of freedom.

Original version by Lukas Atkinson, posted here. Modified by CXW.

chi_squared_test

Return the probability that a given observed distribution was produced by a random process with the given expected distribution. Parameters are as "chi_squared".

If I am reading Knuth correctly, a random sequence should generally have probabilities on the range (0.1, 0.9). TAOCP 3e, vol. 2, p. 47.

Original version by Lukas Atkinson, posted here. Modified by CXW.

chi_squared_maybe_ok

Parameters as "chi_squared_test". Returns true iff the chi-squared result is in the range (0.1, 0.9).

SEE ALSO

• http://blogs.perl.org/users/ovid/2014/01/testing-random-dice-rolls.html
• https://www.nu42.com/2014/01/randomness-and-statistical-concepts.html
• http://oddgeek.info/code/gdp/

BUGS

Please report any bugs or feature requests through the web interface at https://github.com/cxw42/Games-Dice-Tester/issues. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Games::Dice::Tester

You can also look for information at:

• GitHub (main repository)

  https://github.com/cxw42/Games-Dice-Tester

• MetaCPAN

  https://metacpan.org/release/Games-Dice-Tester

• CPAN Ratings

  https://cpanratings.perl.org/d/Games-Dice-Tester

LICENSE

Copyright 2019 Christopher White. Some code Copyright 2014 Lukas Atkinson.

Licensed CC-BY-SA 3.0.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

POD ERRORS

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