Too few arguments error

  public function edit( $id )
  {
    $where = array( 'id' => $id );
        $data['user'] = $this->Admin_model->get_single( 'users' , $where );
        $password = $data['user']->password;

    if (!empty($_POST)) {

      if ($this->form_validation->run('admin_users_create') == true)
      {
        if (empty($_POST['password']))
        {
          $_POST['password']=$password;
        }
        $data = array(
         'name '=> $this->input->post('name', true),
         'email' => $this->input->post('email', true),
         'password' => password_hash($this->input->post('password', true), PASSWORD_BCRYPT),
       );

       $this->session->set_flashdata('alert','Użytkownik dodany poprawnie');
       refresh();
      }
      else{
        $this->session->set_flashdata('alert',validation_errors());
        refresh();
      }
    }
    $this->load->view('admin/users/edit');
  }
  public function unique_email_edit($email)
  {
    $id = $this->uri->segment(4);
    $where = array( 'id' => $id );
    $user = $this->Admin_model->get_single( 'users' , $where );

    if($user->email != $email && $user->id == $id)
    {
      return true;
    }
    else {
      $this->form_validation->set_message('username_check', 'Inny użytkownik ma taki email');
      return false;
    }