function pendulum_euler ( )

%*****************************************************************************80
%
%% pendulum_euler calls euler() with specific values of n, a, b, and y0.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    29 October 2019
%
%  Author:
%
%    John Burkardt
%
  n = 100;
  a = 0.0;
  b = 6.0 * pi;
  u = 1.0;
  v = 0.0;
  y0 = [ u, v ];
  
  [ t, y ] = euler ( @(t,y)pendulum_prime(t,y), n, a, b, y0 );

  plot ( t, y, 'linewidth', 3 );
  grid ( 'on' );
  xlabel ( '<-- T -->' );
  ylabel ( '<-- Y(T) -->' );
  dt = ( b - a ) / n;
  label = sprintf ( 'pendulum ODE with dt = %g\n', dt );
  title ( label );
  filename = 'pendulum.png';
  print ( '-dpng', filename );
  fprintf ( 1, '  Graphics saved as "%s"\n', filename );

  return
end

  
