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.