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

# 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)".

# 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