/**
* The sum of squared weights of contained query clauses.
*
* @return float
*/
public function sumOfSquaredWeights()
{
// compute idf
$this->_idf = $this->_reader->getSimilarity()->idf($this->_query->getTerms(), $this->_reader);
// compute query weight
$this->_queryWeight = $this->_idf * $this->_query->getBoost();
// square it
return $this->_queryWeight * $this->_queryWeight;
}
/**
* Score calculator for non conjunction queries (not all subqueries are required)
*
* @param integer $docId
* @param \Zend\Search\Lucene\SearchIndex $reader
* @return float
*/
public function _nonConjunctionScore($docId, Lucene\SearchIndex $reader)
{
if ($this->_coord === null) {
$this->_coord = array();
$maxCoord = 0;
foreach ($this->_signs as $sign) {
if ($sign !== false /* not prohibited */) {
$maxCoord++;
}
}
for ($count = 0; $count <= $maxCoord; $count++) {
$this->_coord[$count] = $reader->getSimilarity()->coord($count, $maxCoord);
}
}
$score = 0;
$matchedSubqueries = 0;
foreach ($this->_subqueries as $subqueryId => $subquery) {
$subscore = $subquery->score($docId, $reader);
// Prohibited
if ($this->_signs[$subqueryId] === false && $subscore != 0) {
return 0;
}
// is required, but doen't match
if ($this->_signs[$subqueryId] === true && $subscore == 0) {
return 0;
}
if ($subscore != 0) {
$matchedSubqueries++;
$score += $subscore;
}
}
return $score * $this->_coord[$matchedSubqueries] * $this->getBoost();
}
/**
* Score calculator for sloppy phrase queries (terms sequence is fixed)
*
* @param integer $docId
* @param \Zend\Search\Lucene\SearchIndex $reader
* @return float
*/
public function _sloppyPhraseFreq($docId, Lucene\SearchIndex $reader)
{
$freq = 0;
$phraseQueue = array();
$phraseQueue[0] = array(); // empty phrase
$lastTerm = null;
// Walk through the terms to create phrases.
foreach ($this->_terms as $termId => $term) {
$queueSize = count($phraseQueue);
$firstPass = true;
// Walk through the term positions.
// Each term position produces a set of phrases.
foreach ($this->_termsPositions[$termId][$docId] as $termPosition ) {
if ($firstPass) {
for ($count = 0; $count < $queueSize; $count++) {
$phraseQueue[$count][$termId] = $termPosition;
}
} else {
for ($count = 0; $count < $queueSize; $count++) {
if ($lastTerm !== null &&
abs( $termPosition - $phraseQueue[$count][$lastTerm] -
($this->_offsets[$termId] - $this->_offsets[$lastTerm])) > $this->_slop) {
continue;
}
$newPhraseId = count($phraseQueue);
$phraseQueue[$newPhraseId] = $phraseQueue[$count];
$phraseQueue[$newPhraseId][$termId] = $termPosition;
}
}
$firstPass = false;
}
$lastTerm = $termId;
}
foreach ($phraseQueue as $phrasePos) {
$minDistance = null;
for ($shift = -$this->_slop; $shift <= $this->_slop; $shift++) {
$distance = 0;
$start = reset($phrasePos) - reset($this->_offsets) + $shift;
foreach ($this->_terms as $termId => $term) {
$distance += abs($phrasePos[$termId] - $this->_offsets[$termId] - $start);
if($distance > $this->_slop) {
break;
}
}
if ($minDistance === null || $distance < $minDistance) {
$minDistance = $distance;
}
}
if ($minDistance <= $this->_slop) {
$freq += $reader->getSimilarity()->sloppyFreq($minDistance);
}
}
return $freq;
}
/**
* Score specified document
*
* @param integer $docId
* @param \Zend\Search\Lucene\SearchIndex $reader
* @return float
*/
public function score($docId, Lucene\SearchIndex $reader)
{
if (isset($this->_docVector[$docId])) {
return $reader->getSimilarity()->tf($this->_termFreqs[$docId]) *
$this->_weight->getValue() *
$reader->norm($docId, $this->_term->field) *
$this->getBoost();
} else {
return 0;
}
}
/**
* Score calculator for non conjunction queries (not all terms are required)
*
* @param integer $docId
* @param \Zend\Search\Lucene\SearchIndex $reader
* @return float
*/
public function _nonConjunctionScore($docId, $reader)
{
if ($this->_coord === null) {
$this->_coord = array();
$maxCoord = 0;
foreach ($this->_signs as $sign) {
if ($sign !== false) {
$maxCoord++;
}
}
for ($count = 0; $count <= $maxCoord; $count++) {
$this->_coord[$count] = $reader->getSimilarity()->coord($count, $maxCoord);
}
}
$score = 0.0;
$matchedTerms = 0;
foreach ($this->_terms as $termId => $term) {
// Check if term is
if ($this->_signs[$termId] !== false && isset($this->_termsFreqs[$termId][$docId])) {
$matchedTerms++;
/**
* We don't need to check that term freq is not 0
* Score calculation is performed only for matched docs
*/
$score += $reader->getSimilarity()->tf($this->_termsFreqs[$termId][$docId]) * $this->_weights[$termId]->getValue() * $reader->norm($docId, $term->field);
}
}
return $score * $this->_coord[$matchedTerms] * $this->getBoost();
}
