function triangle_orthocenter_2d_test ( )

%*****************************************************************************80
%
%% triangle_orthocenter_2d_test() tests triangle_orthocenter_2d().
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    19 February 2009
%
%  Author:
%
%    John Burkardt
%
  dim_num = 2;
  ntest = 4;

  fprintf ( 1, '\n' );
  fprintf ( 1, 'triangle_orthocenter_2d_test():\n' );
  fprintf ( 1, '  triangle_orthocenter_2d() computes the orthocenter.\n' );

  for i = 1 : ntest

    if ( i == 1 )
      t(1:dim_num,1:3) = [ ...
         0.0,  0.0; ...
         1.0,  0.0; ...
         0.0,  1.0 ]';
    elseif ( i == 2 )
      t(1:dim_num,1:3) = [ ...
         0.0,  0.0; ...
         1.0,  0.0; ...
         0.5,  0.86602539 ]';
    elseif ( i == 3 )
      t(1:dim_num,1:3) = [ ...
         0.0,  0.0; ...
         1.0,  0.0; ...
         0.5, 10.0 ]';
    elseif ( i == 4 )
      t(1:dim_num,1:3) = [ ...
         0.0,  0.0; ...
         1.0,  0.0; ...
        10.0,  2.0 ]';
    end

    r8mat_transpose_print ( dim_num, 3, t, '  Triangle vertices:' );

    [ center, flag ] = triangle_orthocenter_2d ( t );

    r8vec_print ( dim_num, center, '  Orthocenter' );

  end

  return
end
