radius gps

<?php
/**
 * Finds all of the X(table) within (radius) of (object).
 *
 * Uses Haversine formula
 *
 * @author ryan
 */
class Gps_Radius {

    /**
     * @var Doctrine_Connection
     */
    private $doctrine;

    private $table;
    private $object;
    private $radius;
    private $limit = 10;

    private $latitude;
    private $longitude;

    private $results = array();

    public function setDoctrine($doctrine) {
        $this->doctrine = $doctrine;
    }

    public function setTable($table) {
        $this->table = $table;
    }

    public function setObject($object) {
        $this->object = $object;
    }

    public function setRadius($radius) {
        $this->radius = $radius;
    }

    public function setLimit($limit) {
        $this->limit = $limit;
    }

    public function results() {
        return $this->results;
    }

    public function count() {
        return count($this->results);
    }

    /**
     * @return array
     */
    public function find() {

        $this->tableData();
        $this->randomize();
        $this->limit();

        $this->distance();


    }

    private function tableData() {

        $longitude = $this->object->longitude;
        $latitude = $this->object->latitude;
        $radius = $this->radius;

        $lng_min = $longitude - $radius / abs(cos(deg2rad($latitude)) * 69);
        $lng_max = $longitude + $radius / abs(cos(deg2rad($latitude)) * 69);
        $lat_min = $latitude - ($radius / 69);
        $lat_max = $latitude + ($radius / 69);

        $query = $this->doctrine->createQuery()
                ->from(addslashes($this->table) . ' t')
                ->where('latitude between ? and ?', array($lat_min, $lat_max))
                ->andWhere('longitude between ? and ?', array($lng_min, $lng_max));


        $results = $query->execute();

        $this->results = array();

        foreach ($results as $row) {
            if ($row->isViewable()) {
                $this->results[] = array(
                        'object' => $row,
                        'distance' => $this->radius
                );
            }
        }

    }

    private function distance() {

        $newResults = array();
        $latitude = $this->object->latitude;
        $longitude = $this->object->longitude;

        foreach ($this->results as $row) {

            $object = $row['object'];

            $distance = 3956 * 2 *
                    asin(sqrt(pow(sin(($latitude - abs($object->latitude)) * pi() / 180 / 2), 2) +
                    cos($latitude * pi() / 180) * cos(abs($object->latitude) * pi() / 180) *
                    pow(sin(($longitude - $object->longitude) * pi() / 180 / 2), 2)));

            $row['distance'] = $distance;

            $newResults[] = array('object' => $object, 'distance' => $distance);

        }

        $this->results = $newResults;

    }

    private function randomize() {

        // kinda bad that this class is coupled with the search model.  easy
        // to refactor out if things look like they wil lget messy
        usort($this->results, array('Search_Sort_Sort', 'sortByRandom'));

    }

    private function limit() {
        $this->results = array_slice($this->results, 0, $this->limit);
    }


}