Toby Inkster > Math-Erf-Approx-0.002 > Math::Erf::Approx

Download:
Math-Erf-Approx-0.002.tar.gz

Dependencies

Annotate this POD

Website

View/Report Bugs
Module Version: 0.002   Source  

NAME ^

Math::Erf::Approx - pure Perl approximate implementation of the error function

DESCRIPTION ^

This is a pure Perl implementation of the error function (a.k.a. the Gauss error function). It gives an approximation with a maximum absolute difference of 0.0005 from the real value.

Functions

This module can export two functions. Neither is exported by default. This module uses Sub::Exporter, so the functions can be renamed:

 use Math::Erf::Approx -all => { -prefix => 'math_' };
erf($x)

Calculates the result of the error function for value $x.

erfc($x, \&erf)

Given a value $x and a code reference to an implementation of erf(), calculates the complement.

If the code reference is ommitted (which I'd expect would be the most usual case), then the default is the erf function provided by this module.

Testing

It is possible to run a small test suite on this module using:

 use Math::Erf::Approx;
 Math::Erf::Approx->run_tests;

BENCHMARKS ^

Benchmarking against Games::Go::Erf (on a fairly underpowered netbook)...

 Benchmark: timing 100000 iterations of GGE, MEA...
   GGE:  6 wallclock secs ( 6.34 usr +  0.01 sys =  6.35 CPU) @ 15748.03/s (n=100000)
   MEA:  3 wallclock secs ( 2.71 usr +  0.00 sys =  2.71 CPU) @ 36900.37/s (n=100000)

There are considerations other than raw speed though...

SEE ALSO ^

http://en.wikipedia.org/wiki/Error_function.

Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, ed Milton Abramowitz and Irene Stegun. ISBN 0-486-61272-4.

AUTHOR ^

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE ^

This software is copyright (c) 2012 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES ^

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

syntax highlighting: