public function withinCircle($field, $longitude, $latitude, $radius)
    {
        $this->where($field, array(
            '$geoWithin' => array(
                '$center' => array(
                    array($longitude, $latitude),
                    $radius,
                ),
            ),
        ));

        return $this;
    }
public function withinCircle($field, $longitude, $latitude, $radius)
    {
        $this->where($field, array(
            '$geoWithin' => array(
                '$center' => array(
                    array($longitude, $latitude),
                    $radius,
                ),
            ),
        ));

        return $this;
    }
public function withinCircle ( $ field , $ longitude , $ latitude , $ radius ) { $ this -> where ( $ field , array ( '$geoWithin' => array ( '$center' => array ( array ( $ longitude , $ latitude ) , $ radius , ) , ) , ) ) ; return $ this ; }
Select documents with geospatial data within circle defined
by center point and radius in flat surface

@param string $field
@param float $longitude
@param float $latitude
@param float $radius
@return Expression
Select documents with geospatial data within circle defined by center point and radius in flat surface