1 ## Copyright (C) 1995-2012 Kurt Hornik
3 ## This file is part of Octave.
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 3 of the License, or (at
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13 ## General Public License for more details.
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20 ## @deftypefn {Function File} {} logistic_pdf (@var{x})
21 ## For each element of @var{x}, compute the PDF at @var{x} of the
22 ## logistic distribution.
25 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
26 ## Description: PDF of the logistic distribution
28 function pdf = logistic_pdf (x)
35 error ("logistic_pdf: X must not be complex");
38 cdf = logistic_cdf (x);
39 pdf = cdf .* (1 - cdf);
45 %! x = [-Inf -log(4) 0 log(4) Inf];
46 %! y = [0, 0.16, 1/4, 0.16, 0];
47 %!assert(logistic_pdf ([x, NaN]), [y, NaN], eps);
49 %% Test class of input preserved
50 %!assert(logistic_pdf (single([x, NaN])), single([y, NaN]), eps ("single"));
52 %% Test input validation
53 %!error logistic_pdf ()
54 %!error logistic_pdf (1,2)
55 %!error logistic_pdf (i)