---
name: "Catmandu::Stat"
section: "3pm"
platform: "linux"
package: "libcatmandu-stat-perl"
version: "0.13-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Catmandu::Stat"
---

# Catmandu::Stat(3pm)

Catmandu modules for working with statistical data

## NAME

Catmandu::Stat - Catmandu modules for working with statistical data

## SYNOPSIS

```
    # Calculate statistics on the availabity of the ISBN fields in the dataset
    cat data.json | catmandu convert JSON to Stat --fields isbn
    # Preprocess data and calculate statistics
    catmandu convert MARC to Stat --fix 'marc_map(020a,isbn)' --fields isbn < data.mrc
    # Or in fix files
    # Calculate the mean of foo. E.g. foo => [1,2,3,4]
    stat_mean(foo)  # foo => '2.5'
    # Calculate the median of foo. E.g. foo => [1,2,3,4]
    stat_median(foo)  # foo => '2.5'
    # Calculate the standard deviation of foo. E.g. foo => [1,2,3,4]
    stat_stddev(foo)  # foo => '1.12'
    # Calculate the variance of foo. E.g. foo => [1,2,3,4]
    stat_variance(foo)  # foo => '1.25'
```

## MODULES

- •

  Catmandu::Exporter::Stat

- •

  Catmandu::Fix::stat\_mean

- •

  Catmandu::Fix::stat\_median

- •

  Catmandu::Fix::stat\_stddev

- •

  Catmandu::Fix::stat\_variance

## EXAMPLES

The Catmandu::Stat distribution includes a CSV file on the Sacramento crime rate in January 2006, "t/SacramentocrimeJanuary2006.csv" also available at http://samplecsvs.s3.amazonaws.com/SacramentocrimeJanuary2006.csv

To view statistics on the fields available in this file type:

```
    $ catmandu convert CSV to Stat < t/SacramentocrimeJanuary2006.csv
    | name          | count | zeros | zeros% | min | max | mean | variance | stdev | uniq~ | uniq% | entropy   |
    |---------------|-------|-------|--------|-----|-----|------|----------|-------|-------|-------|-----------|
    | #             | 7584  |       |        |     |     |      |          |       |       |       |           |
    | address       | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 5425  | 71.5  | 12.4/12.4 |
    | beat          | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 20    | 0.3   | 4.3/12.9  |
    | cdatetime     | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 5071  | 66.9  | 12.3/12.3 |
    | crimedescr    | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 305   | 4.0   | 5.6/12.6  |
    | district      | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 6     | 0.1   | 2.6/12.9  |
    | grid          | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 537   | 7.1   | 7.8/9.9   |
    | latitude      | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 5288  | 69.7  | 12.4/12.4 |
    | longitude     | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 5295  | 69.8  | 12.4/12.4 |
    | ucr_ncic_code | 7584  | 0     | 0.0    | 1   | 1   | 1    | 0.0      | 0.0   | 88    | 1.2   | 4.1/12.9  |
```

The file has 7584 rows where and all the fields `"address"` to `"ucr_ncic_code"` contain values. Each field has only one value (no arrays available in the CSV file). The are 5492 unique addresses in the CSV file. The `"district"` field has the lowest entropy, most of its values are shared among many rows.

## SEE ALSO

Catmandu, Catmandu::Breaker,

## AUTHOR

Patrick Hochstenbach, `"<patrick.hochstenbach at ugent.be>"`

## LICENSE AND COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.