protected function renew_function_variables()
{
//這邊請用k-means來做
$this->_CI_load('library', 'kals_resource/Webpage', 'webpage');
$function_variables = NULL;
$webpage_id = intval($this->get_field('webpage_id'));
$webpage = new Webpage($webpage_id);
$annotation_coll = $webpage->get_appended_annotation();
//標註數量太少的話就沒有分群的價值，取消分群
if ($annotation_coll->length() < 20) {
return $this;
}
$data = array();
foreach ($annotation_coll as $annotation) {
$data[] = $this->get_feature($annotation);
}
$this->_CI_load('library', 'fuzzy/Output_language_variable_collection', 'output_language_variable_collection');
$membership = new Output_language_variable_collection();
$number = $membership->get_number();
$this->_CI_load('library', 'fuzzy/Clustering', 'clustering');
$clustering = Clustering::get_clustering();
$clustering->set_data($data);
$clustering->set_clusters_number($number);
$positions = $clustering->get_result_positions();
$function_variables = '';
foreach ($positions as $p) {
if ($function_variables != '') {
$function_variables .= ',';
}
$function_variables .= $p;
}
$this->set_field('function_variables', $function_variables);
return $this;
}