/Search/Lucene/Search/Similarity/Default.php
PHP | 110 lines | 32 code | 11 blank | 67 comment | 2 complexity | 1f2d8076916416196e2040ff2adbaad3 MD5 | raw file
- <?php
- /**
- * Zend Framework
- *
- * LICENSE
- *
- * This source file is subject to the new BSD license that is bundled
- * with this package in the file LICENSE.txt.
- * It is also available through the world-wide-web at this URL:
- * http://framework.zend.com/license/new-bsd
- * If you did not receive a copy of the license and are unable to
- * obtain it through the world-wide-web, please send an email
- * to license@zend.com so we can send you a copy immediately.
- *
- * @category Zend
- * @package Zend_Search_Lucene
- * @subpackage Search
- * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- * @version $Id: Default.php 24593 2012-01-05 20:35:02Z matthew $
- */
- /** Zend_Search_Lucene_Search_Similarity */
- require_once 'Zend/Search/Lucene/Search/Similarity.php';
- /**
- * @category Zend
- * @package Zend_Search_Lucene
- * @subpackage Search
- * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- */
- class Zend_Search_Lucene_Search_Similarity_Default extends Zend_Search_Lucene_Search_Similarity
- {
- /**
- * Implemented as '1/sqrt(numTerms)'.
- *
- * @param string $fieldName
- * @param integer $numTerms
- * @return float
- */
- public function lengthNorm($fieldName, $numTerms)
- {
- if ($numTerms == 0) {
- return 1E10;
- }
- return 1.0/sqrt($numTerms);
- }
- /**
- * Implemented as '1/sqrt(sumOfSquaredWeights)'.
- *
- * @param float $sumOfSquaredWeights
- * @return float
- */
- public function queryNorm($sumOfSquaredWeights)
- {
- return 1.0/sqrt($sumOfSquaredWeights);
- }
- /**
- * Implemented as 'sqrt(freq)'.
- *
- * @param float $freq
- * @return float
- */
- public function tf($freq)
- {
- return sqrt($freq);
- }
- /**
- * Implemented as '1/(distance + 1)'.
- *
- * @param integer $distance
- * @return float
- */
- public function sloppyFreq($distance)
- {
- return 1.0/($distance + 1);
- }
- /**
- * Implemented as 'log(numDocs/(docFreq+1)) + 1'.
- *
- * @param integer $docFreq
- * @param integer $numDocs
- * @return float
- */
- public function idfFreq($docFreq, $numDocs)
- {
- return log($numDocs/(float)($docFreq+1)) + 1.0;
- }
- /**
- * Implemented as 'overlap/maxOverlap'.
- *
- * @param integer $overlap
- * @param integer $maxOverlap
- * @return float
- */
- public function coord($overlap, $maxOverlap)
- {
- return $overlap/(float)$maxOverlap;
- }
- }