Codeigniter:Pagination setup (standard)

pagination_setup.php

        //pagination
        $this->load->library('pagination');

        $per_page = 15;
        $config['uri_segment'] = 3;
        $config['base_url'] = '/';
        $config['anchor_class'] = ' class="pagination" ';
        $config['total_rows'] = TOTAL_RECORDS;
        $config['per_page'] = $per_page; 
        $config['use_page_numbers'] = TRUE;
        $choice = $config["total_rows"] / $config["per_page"];
        $config["num_links"] = round($choice);
        $this->pagination->initialize($config); 
        $page = ($this->uri->segment(3))? $this->uri->segment(3) : 0;

        $data['pagination'] = $this->pagination->create_links();