function cdf = logistic_my_cdf ( x, a, b )

%*****************************************************************************80
%
%% logistic_my_cdf() evaluates the Logistic CDF.
%
%  Discussion:
%
%    Had to insert the idiotic "_my" in the name because Octave has a
%    similarly named function in its automatically installed package.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    13 September 2004
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real X, the argument of the CDF.
%
%    real A, B, the parameters of the PDF.
%    0.0 < B.
%
%  Output:
%
%    real CDF, the value of the CDF.
%
  cdf = 1.0 ./ ( 1.0 + exp ( ( a - x ) / b ) );

  return
end
