1## Copyright (C) 2016 Dag Lyberg 2## Copyright (C) 1995-2015 Kurt Hornik 3## 4## This file is part of Octave. 5## 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. 10## 11## Octave is distributed in the hope that it will be useful, but 12## WITHOUT ANY WARRANTY; without even the implied warranty of 13## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14## General Public License for more details. 15## 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/>. 19 20## -*- texinfo -*- 21## @deftypefn {} {} nakacdf (@var{x}, @var{m}, @var{w}) 22## For each element of @var{x}, compute the cumulative distribution function 23## (CDF) at @var{x} of the Nakagami distribution with shape parameter @var{m} 24## and scale parameter @var{w}. 25## 26## @end deftypefn 27 28## Author: Dag Lyberg <daglyberg80@gmail.com> 29## Description: CDF of the Nakagami distribution 30 31function cdf = nakacdf (x, m, w) 32 33 if (nargin != 3) 34 print_usage (); 35 endif 36 37 if (! isscalar (m) || ! isscalar (w)) 38 [retval, x, m, w] = common_size (x, m, w); 39 if (retval > 0) 40 error ("nakacdf: X, M and W must be of common size or scalars"); 41 endif 42 endif 43 44 if (iscomplex (x) || iscomplex (m) || iscomplex (w)) 45 error ("nakacdf: X, M and W must not be complex"); 46 endif 47 48 if (isa (x, "single") || isa (m, "single") || isa (w, "single")) 49 inv = zeros (size (x), "single"); 50 else 51 inv = zeros (size (x)); 52 endif 53 54 k = isnan (x) | ! (m > 0) | ! (w > 0); 55 cdf(k) = NaN; 56 57 k = (x == Inf) & (0 < m) & (m < Inf) & (0 < w) & (w < Inf); 58 cdf(k) = 1; 59 60 k = (0 < x) & (x < Inf) & (0 < m) & (m < Inf) & (0 < w) & (w < Inf); 61 if (isscalar(x) && isscalar (m) && isscalar(w)) 62 left = m; 63 right = (m/w) * x^2; 64 cdf(k) = gammainc(right, left); 65 elseif (isscalar (m) && isscalar(w)) 66 left = m * ones(size(x)); 67 right = (m/w) * x.^2; 68 cdf(k) = gammainc(right(k), left(k)); 69 else 70 left = m .* ones(size(x)); 71 right = (m./w) .* x.^2; 72 cdf(k) = gammainc(right(k), left(k)); 73 endif 74 75endfunction 76 77 78%!shared x,y 79%! x = [-1, 0, 1, 2, Inf]; 80%! y = [0, 0, 0.63212055882855778, 0.98168436111126578, 1]; 81%!assert (nakacdf (x, ones (1,5), ones (1,5)), y, eps) 82%!assert (nakacdf (x, 1, 1), y, eps) 83%!assert (nakacdf (x, [1, 1, NaN, 1, 1], 1), [y(1:2), NaN, y(4:5)]) 84%!assert (nakacdf (x, 1, [1, 1, NaN, 1, 1]), [y(1:2), NaN, y(4:5)]) 85%!assert (nakacdf ([x, NaN], 1, 1), [y, NaN], eps) 86 87## Test class of input preserved 88%!assert (nakacdf (single ([x, NaN]), 1, 1), single ([y, NaN]), eps('single')) 89%!assert (nakacdf ([x, NaN], single (1), 1), single ([y, NaN]), eps('single')) 90%!assert (nakacdf ([x, NaN], 1, single (1)), single ([y, NaN]), eps('single')) 91 92## Test input validation 93%!error nakacdf () 94%!error nakacdf (1) 95%!error nakacdf (1,2) 96%!error nakacdf (1,2,3,4) 97%!error nakacdf (ones (3), ones (2), ones(2)) 98%!error nakacdf (ones (2), ones (3), ones(2)) 99%!error nakacdf (ones (2), ones (2), ones(3)) 100%!error nakacdf (i, 2, 2) 101%!error nakacdf (2, i, 2) 102%!error nakacdf (2, 2, i) 103 104