# FreeBSD Manual Pages

```Lite(3)		      User Contributed Perl Documentation	       Lite(3)

NAME
Statistics::Lite	- Small	stats stuff.

SYNOPSIS
use Statistics::Lite qw(:all);

\$min= min @data;
\$mean= mean @data;

%data= statshash	@data;
print "sum= \$data{sum} stddev= \$data{stddev}\n";

print statsinfo(@data);

DESCRIPTION
This module is a	lightweight, functional	alternative to larger, more
complete, object-oriented statistics packages.  As such,	it is likely
to be better suited, in general,	to smaller data	sets.

This is also a module for dilettantes.

When you	just want something to give some very basic, high-school-level
statistical values, without having to set up and	populate an object
first, this module may be useful.

NOTE
This module implements standard deviation and variance calculated by
both the	unbiased and biased estimators.

FUNCTIONS
"min(@data)", "max(@data)", "range(@data)", "sum(@data)",
"count(@data)"
Returns the minimum value, maximum value, range (max	- min),	sum,
or count of values in @data.	Undefined values are ignored.

"count(@data)" simply returns "scalar(@data)".

Please note that this module	does not ignore	undefined values in
your	data; instead, those are treated as zero.

"mean(@data)", "median(@data)", "mode(@data)"
Calculates the mean,	median,	or mode	average	of the values in
@data. Undefined values are ignored.	 (In the event of ties in the
mode	average, their mean is returned.)

"variance(@data)", "stddev(@data)"
Returns the standard	deviation or variance of @data for a sample
(same as Excel's STDEV).  This is also called the Unbiased Sample
Variance and	involves dividing the sample's squared deviations by
N-1 (the sample count minus 1).  The	standard deviation is just the
square root of the variance.

"variancep(@data)", "stddevp(@data)"
Returns the standard	deviation or variance of @data for the
population (same as Excel's STDEVP).	 This involves dividing	the
squared deviations of the population	by N (the population size).
The standard	deviation is just the square root of the variance.

"statshash(@data)"
Returns a hash whose	keys are the names of all the functions	listed
above, with the corresponding values, calculated for	the data set.

"statsinfo(@data)"
Returns a string describing the data	set, using the values detailed
above.

"frequencies(@data)"
Returns a hash. The keys are	the distinct values in the data	set,
and the values are the number of times that value occurred in the
data	set.

Import Tags
The ":all" import tag imports all exportable functions from this	module
into the	current	namespace (use with caution). More specifically, these
functions are the following: "min", "max", "range", "sum", "count",
"mean", "median", "mode", "variance", "stddev", "variancep", "stddevp",
"statshash", "statsinfo", and "frequencies".

To import the statistical functions, use	the import tag ":funcs".  This
imports all of the above-mentioned functions, except for	"statshash",
"statsinfo", and	"frequencies".

Use ":stats" to import "statshash(@data)" and "statsinfo(@data)".

REPOSITORY
<https://github.com/brianary/Statistics-Lite>

AUTHOR
Brian Lalonde <brian@webcoder.info>, "stddev(@data)", "stddevp(@data)",
"variance(@data)", "variancep(@data)", additional motivation by Nathan
Haigh, with kind	support	from Alexander Zangerl.

The project lives at https://github.com/brianary/Statistics-Lite

Copyright 2000 Brian Lalonde <brian@webcoder.info>, Nathan Haigh,
Alexander Zangerl, and Ton Voon.

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