function value = jump_fp ( x )

%*****************************************************************************80
%
%% jump_fp evaluates the derivative of the jump function.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    21 September 2019
%
%  Input:
%
%    real x, the argument.
%
%  Output:
%
%    real value, the function value.
%
  value = - sin ( x ) * exp ( cos ( x ) ) - 1.0 / 2.0;

  return
end

