1 ## Copyright (C) 2012 Rik Wehbring
2 ## Copyright (C) 1997-2012 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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14 ## General Public License for more details.
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21 ## @deftypefn {Function File} {} hygecdf (@var{x}, @var{t}, @var{m}, @var{n})
22 ## Compute the cumulative distribution function (CDF) at @var{x} of the
23 ## hypergeometric distribution with parameters @var{t}, @var{m}, and
24 ## @var{n}. This is the probability of obtaining not more than @var{x}
25 ## marked items when randomly drawing a sample of size @var{n} without
26 ## replacement from a population of total size @var{t} containing
27 ## @var{m} marked items.
29 ## The parameters @var{t}, @var{m}, and @var{n} must be positive integers
30 ## with @var{m} and @var{n} not greater than @var{t}.
33 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
34 ## Description: CDF of the hypergeometric distribution
36 function cdf = hygecdf (x, t, m, n)
42 if (!isscalar (t) || !isscalar (m) || !isscalar (n))
43 [retval, x, t, m, n] = common_size (x, t, m, n);
45 error ("hygecdf: X, T, M, and N must be of common size or scalars");
49 if (iscomplex (x) || iscomplex (t) || iscomplex (m) || iscomplex (n))
50 error ("hygecdf: X, T, M, and N must not be complex");
53 if (isa (x, "single") || isa (t, "single") || isa (m, "single") || isa (n, "single"))
54 cdf = NaN (size (x), "single");
59 ok = ((t >= 0) & (m >= 0) & (n > 0) & (m <= t) & (n <= t) &
60 (t == fix (t)) & (m == fix (m)) & (n == fix (n)));
64 cdf = discrete_cdf (x, 0 : n, hygepdf (0 : n, t, m, n));
67 for i = find (ok(:)') # Must be row vector arg to for loop
69 cdf(i) = discrete_cdf (x(i), v, hygepdf (v, t(i), m(i), n(i)));
78 %! y = [0 1/6 5/6 1 1];
79 %!assert(hygecdf (x, 4*ones(1,5), 2, 2), y, eps);
80 %!assert(hygecdf (x, 4, 2*ones(1,5), 2), y, eps);
81 %!assert(hygecdf (x, 4, 2, 2*ones(1,5)), y, eps);
82 %!assert(hygecdf (x, 4*[1 -1 NaN 1.1 1], 2, 2), [y(1) NaN NaN NaN y(5)], eps);
83 %!assert(hygecdf (x, 4, 2*[1 -1 NaN 1.1 1], 2), [y(1) NaN NaN NaN y(5)], eps);
84 %!assert(hygecdf (x, 4, 5, 2), [NaN NaN NaN NaN NaN]);
85 %!assert(hygecdf (x, 4, 2, 2*[1 -1 NaN 1.1 1]), [y(1) NaN NaN NaN y(5)], eps);
86 %!assert(hygecdf (x, 4, 2, 5), [NaN NaN NaN NaN NaN]);
87 %!assert(hygecdf ([x(1:2) NaN x(4:5)], 4, 2, 2), [y(1:2) NaN y(4:5)], eps);
89 %% Test class of input preserved
90 %!assert(hygecdf ([x, NaN], 4, 2, 2), [y, NaN], eps);
91 %!assert(hygecdf (single([x, NaN]), 4, 2, 2), single([y, NaN]), eps("single"));
92 %!assert(hygecdf ([x, NaN], single(4), 2, 2), single([y, NaN]), eps("single"));
93 %!assert(hygecdf ([x, NaN], 4, single(2), 2), single([y, NaN]), eps("single"));
94 %!assert(hygecdf ([x, NaN], 4, 2, single(2)), single([y, NaN]), eps("single"));
96 %% Test input validation
100 %!error hygecdf (1,2,3)
101 %!error hygecdf (1,2,3,4,5)
102 %!error hygecdf (ones(2), ones(3), 1, 1)
103 %!error hygecdf (1, ones(2), ones(3), 1)
104 %!error hygecdf (1, 1, ones(2), ones(3))
105 %!error hygecdf (i, 2, 2, 2)
106 %!error hygecdf (2, i, 2, 2)
107 %!error hygecdf (2, 2, i, 2)
108 %!error hygecdf (2, 2, 2, i)