NAME

AI::ConfusionMatrix - make a confusion matrix

SYNOPSIS

my %matrix;

Loop over your tests

---

$matrix{$expected}{$predicted} += 1;

---

makeConfusionMatrix(\%matrix, 'output.csv');

DESCRIPTION

This module prints a confusion matrix from a hash reference. This module tries to be generic enough to be used within a lot of machine learning projects.

Function

makeConfusionMatrix($hash_ref, $file)

This function makes a confusion matrix from $hash_ref and writes it to $file. $file can be a filename or a file handle opened with the w+ mode.

Examples:

makeConfusionMatrix(\%matrix, 'output.csv');
makeConfusionMatrix(\%matrix, *$fh);

The hash reference must look like this :

$VAR1 = {


          'value_expected1' => {
                      'value_predicted1' => value
                    },
          'value_expected2' => {
                      'value_predicted1' => value,
                      'value_predicted2' => value
                    },
          'value_expected3' => {
                      'value_predicted3' => value
                    }

        };

The output will be in CSV. Here is an example:

,1997,1998,2001,2003,2005,2008,2012,2015,TOTAL,TP,FP,FN,ACC
1997,2,,,,,,,,2,2,0,0,100.00%
1998,,1,,,,,,,1,1,0,0,100.00%
2001,,,1,,,,,,1,1,0,0,100.00%
2003,,,,5,,,1,1,7,5,0,2,71.43%
2005,,,,,7,,,2,9,7,0,2,77.78%
2008,,,,,,3,,,3,3,0,0,100.00%
2012,,,,,,,5,,5,5,1,0,100.00%
2015,,,,,,,,8,8,8,3,0,100.00%
TOTAL,2,1,1,5,7,3,6,11,36,32,4,4,88.89%

Prettified:

|       | 1997 | 1998 | 2001 | 2003 | 2005 | 2008 | 2012 | 2015 | TOTAL | TP | FP | FN | ACC     |
|-------|------|------|------|------|------|------|------|------|-------|----|----|----|---------|
| 1997  | 2    |      |      |      |      |      |      |      | 2     | 2  | 0  | 0  | 100.00% |
| 1998  |      | 1    |      |      |      |      |      |      | 1     | 1  | 0  | 0  | 100.00% |
| 2001  |      |      | 1    |      |      |      |      |      | 1     | 1  | 0  | 0  | 100.00% |
| 2003  |      |      |      | 5    |      |      | 1    | 1    | 7     | 5  | 0  | 2  | 71.43%  |
| 2005  |      |      |      |      | 7    |      |      | 2    | 9     | 7  | 0  | 2  | 77.78%  |
| 2008  |      |      |      |      |      | 3    |      |      | 3     | 3  | 0  | 0  | 100.00% |
| 2012  |      |      |      |      |      |      | 5    |      | 5     | 5  | 1  | 0  | 100.00% |
| 2015  |      |      |      |      |      |      |      | 8    | 8     | 8  | 3  | 0  | 100.00% |
| TOTAL | 2    | 1    | 1    | 5    | 7    | 3    | 6    | 11   | 36    | 32 | 4  | 4  | 88.89%  |

TP:

True Positive

FP:

False Positive

FN:

False Negative

ACC:

Accuracy

AUTHOR

Vincent Lequertier <sky@riseup.net>

LICENSE

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