function w = exact ( x, y )

%*****************************************************************************80
%
%% exact() calculates the exact function.
%
%  Discussion:
%
%    The function specified here depends on the problem being solved.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    28 November 2008
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real X, Y, the coordinates of a point in the region.
%
%  Output:
%
%    real W, the value of the function W(X,Y).
%
  w = sin ( pi * x ) * sin ( pi * y ) + x;

  return
end

