function x = rng_cliff_next ( x )

%*****************************************************************************80
%
%% rng_cliff_next returns the next entry for the Cliff random number generator.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    12 August 2019
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real x, the current entry.
%    0 < x < 1.
%
%  Output:
%
%    real x, the next entry.
%
  if ( x <= 0.0 || 1 <= x )
    x = NaN;
  else
    x = mod ( - 100.0 * log ( x ), 1.0 );
  end

  return
end
