function value = uexact ( x )

%% UEXACT returns the value of the exact solution at any point X.
%
%  Modified:
%
%    05 November 2006
%
%  Parameters:
%
%    Input, real X, the evaluation point.
%
%    Output, real VALUE, the value of the exact solution at X.
%

%
%  Find out which problem we're working on.
%
  problem = get_problem ( 'DUMMY' );

  if ( problem == 1 )
    value = x;
  elseif ( problem == 2 )
    value = x^2;
  elseif ( problem == 3 )
    value = sin ( pi * x / 2.0 );
  elseif ( problem == 4 )
    value = cos ( pi * x / 2.0 );
  elseif ( problem == 5 )
    beta = get_beta ( 'DUMMY' );
    value = ( x^( beta + 2.0 ) ) ...
      / ( ( beta + 2.0 ) * ( beta + 1.0 ) );
  elseif ( problem == 6 )
    alpha = get_alpha ( 'DUMMY' );
    value = atan ( ( x - 0.5 ) / alpha );
  else
    value = 0.0;
  end