Файл: library/Zend/Search/Lucene/Search/Similarity/Default.php
Строк: 108
<?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) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: Default.php 20096 2010-01-06 02:05:09Z bkarwin $
*/
/** Zend_Search_Lucene_Search_Similarity */
require_once 'Zend/Search/Lucene/Search/Similarity.php';
/**
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Search
* @copyright Copyright (c) 2005-2010 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;
}
}