function octave_mistake_test04 ( )

%*****************************************************************************80
%
%% octave_mistake_test04() tries to take the absolute value.
%
%  Discussion:
%
%    The statement
%
%      abs x
%
%    is almost certainly misguided, but does not result in an error
%    message, and produces a numeric result!
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    25 August 2017
%
%  Author:
%
%    John Burkardt
%
  fprintf ( 1, '\n' );
  fprintf ( 1, 'octave_mistake_test04():\n' );
  fprintf ( 1, '  y = abs x fails.\n' );

  x = 123.456
%
%  #1:
%
  abs ( x )
%
%  #2:
%
  abs x
%
%  #3: Now try this, which is a clue to what is going on.
%
  abs banana

  return
end

