Calling class name as if a method in CodeIgniter emits "Call to undefined method" error

I want to update some data in mysql. Here is my controller:

class Ci_update extends CI_Controller
{
    function __construct() {
        parent::__construct();
    }
    
    function index()
    {
        $data = array
        (
          'title' => 'Data Structure using C',  
          'text' => 'Data Structure Using C, for, IIIrd Sem VTU CSE students'
        );
        $id = 4;
        
        $this->load->model('ci_update_model');
        $this->ci_update_model($data, $id);
    }
}

and my model:

class Ci_update_model extends CI_Model
{
    function __construct() {
        parent::__construct();
    }
    
    function updateData($data, $id)
    {
        $this->db->where('id',$id);
        $this->db->update('data', $data);
    }
}

But when I tried to run the program, it says

Call to undefined method Ci_update::ci_update_model() in C:\wamp\www\ci\application\controllers\ci_update.php on line 19

What am I doing wrong?

Use as below

$this->load->model('ci_update_model');
$this->ci_update_model->updateData($data,$id);