function triangle_quality_test ( )

%*****************************************************************************80
%
%% TRIANGLE_QUALITY_TEST tests TRIANGLE_QUALITY.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    19 February 2009
%
%  Author:
%
%    John Burkardt
%
  ntest = 4;

  fprintf ( 1, '\n' );
  fprintf ( 1, 'TRIANGLE_QUALITY_TEST\n' );
  fprintf ( 1, '  TRIANGLE_QUALITY computes the quality of a triangle.\n' );

  for i = 1 : ntest

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

    r8mat_transpose_print ( 2, 3, t, '  Triangle vertices:' );

    quality = triangle_quality ( t );

    fprintf ( 1, '\n' );
    fprintf ( 1, '  Quality = %f\n', quality );

  end

  return
end
