public function index()
{
    $this->load->model("regression_model") ;
    $array = $this->regression_model->display_data();
    $targets = $this->regression_model->display_data2();

    $matrix = new Matrix($array);
    $set = new Set($targets);

    $arraytrix = $matrix->toArray();
    $arrayset = $set->toArray();

    $col[] = array_column($arraytrix, 'year');
    $col2[] = array_column($arrayset, 'total');

    var_dump($col);
    var_dump($col2);

    $regression = new LeastSquares();
    $regression->train($col, $col2);

    $predicted = $regression->predict([2018]);

    var_dump($predicted);

    $this->load->view('regression');

}

function display_data()
{
    $query1 = $this->db->query("SELECT year from total_year");
    return $query1->result_array();

}
function display_data2()
{
    $query1 = $this->db->query("SELECT total from total_year");
    return $query1->result_array();
}