NAME

Statistics::Descriptive::PDL - A close to drop-in replacement for Statistics::Descriptive using PDL as the back-end

VERSION

Version 0.11

SYNOPSIS

use Statistics::Descriptive::PDL;

my $stats = Statistics::Descriptive::PDL->new();
$stats->add_data(1,2,3,4);
my $mean = $stats->mean;
my $var  = $stats->variance();

DESCRIPTION

This module provides basic functions used in descriptive statistics.

METHODS

new

Create a new statistics object. Takes no arguments.

add_data (@data)

add_data (\@data)

Add data to the stats object. Passed through to the underlying PDL object. Appends to any existing data.

Multidimensional data are flattened into a single dimensional array.

get_data

Return the data as a perl array. Returns an array ref in scalar context.

get_data_as_hash

Returns the data as a perl hash, with the unique data values as the hash keys and the counts of each unique data value as the hash values.

Deduplicates the data if needed, incrementing the weights as appropriate. Internally it uses a Statistics::Descriptive::PDL::SampleWeighted object.

Data values are stringified so there is obviously potential for loss of precision.

values_are_unique

Flag whether the data have duplicate values. Has no effect on unweighted data. It is provided purely for a consistent interface with the weighted variants.

clear_cache

Clears any cached results on an object.

available_stats

Method to return a list of the available statistics.

geometric_mean

harmonic_mean

max

mean

median

min

mode

sample_range

standard_deviation

sum

variance

The above should need no explanation, except that they use the unbiased methods where appropriate, as per Statistics::Descriptive.

count

Number of data items that have been added.

skewness

kurtosis

Skewness and kurtosis to match that of MS Excel. If you are used to R then these are the same as type=2 in e1071::skewness and e1071::kurtosis.

sd

stdev

These are aliases for the standard_deviation method.

percentile (10)

percentile (45)

The percentile calculation differs from Statistics::Descriptive in that it uses linear interpolation to determine the values, and thus does not return the exact same values as the input data.

percentiles (10, 20, 30)

A simple wrapper around the percentile method to allow calculation of multiple values in one call.

iqr

The inter-quartile range. A convenience method to calculate the difference between the 75th and 25th percentile.

sum_weights

sum_sqr_weights

These are both the same as the count. They are provided for compatibility with the weighted variants.

Not yet implemented, and possibly won't be.

Any of the trimmed functions, frequency functions and some others.

least_squares_fit

trimmed_mean

quantile

mindex

maxdex

AUTHOR

Shawn Laffan, <shawnlaffan at gmail.com>

BUGS

Please report any bugs or feature requests to https://github.com/shawnlaffan/Statistics-Descriptive-PDL/issues.

ACKNOWLEDGEMENTS

LICENSE AND COPYRIGHT

Copyright 2021 Shawn Laffan.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

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This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

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