function value = p01_exact ( )

%*****************************************************************************80
%
%% P01_EXACT returns the exact integral of function 1 over the unit circle.
%
%  Discussion:
%
%    The integral depends on a parameter E which must be set by calling
%    P01_PARAM_SET ( E ) before calling this function.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    27 December 2013
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Output, real VALUE, the exact integral.
%
  e = p01_param_get ( );

  value = cos_power_int ( 0.0, 2.0 * pi, e ) / ( e + 2 );

  return
end
