1 ## Copyright (C) 2012 Rik Wehbring
2 ## Copyright (C) 1995-2012 Kurt Hornik
4 ## This file is part of Octave.
6 ## Octave is free software; you can redistribute it and/or modify it
7 ## under the terms of the GNU General Public License as published by
8 ## the Free Software Foundation; either version 3 of the License, or (at
9 ## your option) any later version.
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13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 ## General Public License for more details.
16 ## You should have received a copy of the GNU General Public License
17 ## along with Octave; see the file COPYING. If not, see
18 ## <http://www.gnu.org/licenses/>.
21 ## @deftypefn {Function File} {} geocdf (@var{x}, @var{p})
22 ## For each element of @var{x}, compute the cumulative distribution function
23 ## (CDF) at @var{x} of the geometric distribution with parameter @var{p}.
26 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
27 ## Description: CDF of the geometric distribution
29 function cdf = geocdf (x, p)
36 [retval, x, p] = common_size (x, p);
38 error ("geocdf: X and P must be of common size or scalars");
42 if (iscomplex (x) || iscomplex (p))
43 error ("geocdf: X and P must not be complex");
46 if (isa (x, "single") || isa (p, "single"))
47 cdf = zeros (size (x), "single");
49 cdf = zeros (size (x));
52 k = isnan (x) | !(p >= 0) | !(p <= 1);
55 k = (x == Inf) & (p >= 0) & (p <= 1);
58 k = (x >= 0) & (x < Inf) & (x == fix (x)) & (p > 0) & (p <= 1);
60 cdf(k) = 1 - ((1 - p) .^ (x(k) + 1));
62 cdf(k) = 1 - ((1 - p(k)) .^ (x(k) + 1));
70 %! y = [0 0.5 0.75 1];
71 %!assert(geocdf (x, 0.5*ones(1,4)), y);
72 %!assert(geocdf (x, 0.5), y);
73 %!assert(geocdf (x, 0.5*[-1 NaN 4 1]), [NaN NaN NaN y(4)]);
74 %!assert(geocdf ([x(1:2) NaN x(4)], 0.5), [y(1:2) NaN y(4)]);
76 %% Test class of input preserved
77 %!assert(geocdf ([x, NaN], 0.5), [y, NaN]);
78 %!assert(geocdf (single([x, NaN]), 0.5), single([y, NaN]));
79 %!assert(geocdf ([x, NaN], single(0.5)), single([y, NaN]));
81 %% Test input validation
84 %!error geocdf (1,2,3)
85 %!error geocdf (ones(3),ones(2))
86 %!error geocdf (ones(2),ones(3))