Created
December 14, 2013 19:17
-
-
Save dedurus/7963585 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<?php | |
/** | |
* Return the coefficient of two items based on Jaccard index | |
* http://en.wikipedia.org/wiki/Jaccard_index | |
* | |
* Example: | |
* | |
* $tags1 = "code, php, jaccard, test, items"; | |
* $tags2 = "test, code"; | |
* echo getSimilarityCoefficient( $tags1, $tags2 ); // 0.28 | |
* | |
* $str1 = "similarity coefficient of two items"; | |
* $str2 = "two items are cool"; | |
* echo getSimilarityCoefficient( $str1, $str2, " " ); // 0.44 | |
* | |
* @param string $item1 | |
* @param string $item2 | |
* @param string $separator | |
* @return float | |
* @author Henrique Hohmann | |
* @version 0.1 | |
*/ | |
function getSimilarityCoefficient( $item1, $item2, $separator = "," ) { | |
$item1 = explode( $separator, $item1 ); | |
$item2 = explode( $separator, $item2 ); | |
$arr_intersection = array_intersect( $item2, $item2 ); | |
$arr_union = array_merge( $item1, $item2 ); | |
$coefficient = count( $arr_intersection ) / count( $arr_union ); | |
return $coefficient; | |
} | |
?> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment