function isbn_digit_to_i4_test ( )

%*****************************************************************************80
%
%% isbn_digit_to_i4_test() tests isbn_digit_to_i4().
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    16 September 2015
%
%  Author:
%
%    John Burkardt
%
  c_test = [ ...
    '0', '1', '2', '3', '4', ...
    '5', '6', '7', '8', '9', ...
    'X', 'x', 'Y', '*', '?', ...
    ' ' ];

  fprintf ( 1, '\n' );
  fprintf ( 1, 'isbn_digit_to_i4_test():\n' );
  fprintf ( 1, '  isbn_digit_to_i4() converts an ISBN digit to an I4\n' );
  fprintf ( 1, '\n' );

  for i = 1 : 11
    c = c_test(i);
    i4 = isbn_digit_to_i4 ( c );
    fprintf ( 1, '  %c      %2d\n', c, i4 );
  end

  return
end
