final move of files

[web.mtrack] / Zend / Search / Lucene / Search / Similarity / Default.php

diff --git a/Zend/Search/Lucene/Search/Similarity/Default.php b/Zend/Search/Lucene/Search/Similarity/Default.php
new file mode 100644 (file)
index 0000000..8bcd3f0
--- /dev/null
+++ b/Zend/Search/Lucene/Search/Similarity/Default.php
@@ -0,0 +1,110 @@
+<?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) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id: Default.php 16541 2009-07-07 06:59:03Z 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) 2005-2009 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;
+    }
+}