Author image Daniel S. T. Hughes

NAME

Statistics::Distributions::Bartlett - Bartlett's test for equal sample variances.

VERSION

This document describes Statistics::Distributions::Bartlett version 0.0.2

SYNOPSIS

    use Statistics::Distributions::Bartlett;
                           
    # Create data to pass as ARRAY/ARRAY references
    my @a = [qw/4534543  543 453 5 543 534 5 4 543 543 6 534 54 3 534  534 54 5/];
    my @b = [qw/ 546 565 65 64  5 434 65 457 67 78 6  34 2 6 57 43  2 556 7 4563/];
    my @c = [qw/ 565 44 535 6678 787 5 5/];
                             
    # Call exported sub routine on ARRAY references of data to print result to STDOUT.
    &bartlett(\@a,\@b,\@c);

    # Call in LIST-context to access results directly:
    my ($K, $p_val, $df, $k, $n_total ) = &bartlett(\@a,\@b,\@c);

DESCRIPTION

Bartlett test is used to test if k samples have equal variances. Such homogeneity is often assumed by other statistical tests and consequently the Bartlett test should be used to verify that assumption. See http://www.itl.nist.gov/div898/handbook/eda/section3/eda357.htm.

DEPENDENCIES

'Statistics::Distributions' => '1.02', 'Carp' => '1.08', 'List::Util' => '1.19',

BUGS

Let me know.

AUTHOR

Daniel S. T. Hughes <dsth@cantab.net>

LICENCE AND COPYRIGHT

Copyright (c) 2010, Daniel S. T. Hughes <dsth@cantab.net>. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

DISCLAIMER OF WARRANTY

Because this software is licensed free of charge, there is no warranty for the software, to the extent permitted by applicable law. Except when otherwise stated in writing the copyright holders and/or other parties provide the software "as is" without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the software is with you. Should the software prove defective, you assume the cost of all necessary servicing, repair, or correction.

In no event unless required by applicable law or agreed to in writing will any copyright holder, or any other party who may modify and/or redistribute the software as permitted by the above licence, be liable to you for damages, including any general, special, incidental, or consequential damages arising out of the use or inability to use the software (including but not limited to loss of data or data being rendered inaccurate or losses sustained by you or third parties or a failure of the software to operate with any other software), even if such holder or other party has been advised of the possibility of such damages. =CUT