Online PHP editor | refs for 48UZL

<?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 * @author Alex Rock * @version 0.2 */ function getSimilarityCoefficient( $item1, $item2, $separator = "," ) { $item1 = array_unique(array_map('trim', explode( $separator, strtolower($item1) ))); $item2 = array_unique(array_map('trim', explode( $separator, strtolower($item2) ))); $arr_intersection = array_intersect( $item2, $item1 ); $arr_union = array_unique(array_merge( $item1, $item2 )); $coefficient = count( $arr_intersection ) / count( $arr_union ); return $coefficient; } $tags1 = "code, test"; $tags2 = "test, code"; echo getSimilarityCoefficient( $tags1, $tags2 ); echo "\n"; $tags1 = "test, code"; $tags2 = "test, code"; echo getSimilarityCoefficient( $tags1, $tags2 ); echo "\n"; $str1 = "two items that are cool"; $str2 = "two items are cool"; echo getSimilarityCoefficient( $str1, $str2, " " ); echo "\n"; $str1 = "I've got two COOL items"; $str2 = "two items are cool"; echo getSimilarityCoefficient( $str1, $str2, " " );