Mercurial > jwe > octave
view scripts/statistics/discrete_rnd.m @ 25166:883564a561aa stable
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* texinfo-parser.cc, texinfo-parser.h, webinfo.cc, webinfo.h, lo-regexp.cc,
lo-regexp.h, cmpermute.m, cmunique.m, findfigs.m, bicg.m, bicgstab.m, cgs.m,
discrete_cdf.m, discrete_inv.m, discrete_pdf.m, discrete_rnd.m,
empirical_cdf.m, empirical_inv.m, empirical_pdf.m, empirical_rnd.m, strjoin.m:
List current copyright holder first in list of copyrights.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 08 Apr 2018 18:30:57 -0700 |
parents | 6652d3823428 |
children | 00f796120a6d |
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## Copyright (C) 1996-2018 Kurt Hornik ## Copyright (C) 2012 Rik Wehbring ## ## This file is part of Octave. ## ## Octave is free software: you can redistribute it and/or modify it ## under the terms of the GNU General Public License as published by ## the Free Software Foundation, either version 3 of the License, or ## (at your option) any later version. ## ## Octave is distributed in the hope that it will be useful, but ## WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, see ## <https://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {} {} discrete_rnd (@var{v}, @var{p}) ## @deftypefnx {} {} discrete_rnd (@var{v}, @var{p}, @var{r}) ## @deftypefnx {} {} discrete_rnd (@var{v}, @var{p}, @var{r}, @var{c}, @dots{}) ## @deftypefnx {} {} discrete_rnd (@var{v}, @var{p}, [@var{sz}]) ## Return a matrix of random samples from the univariate distribution which ## assumes the values in @var{v} with probabilities @var{p}. ## ## When called with a single size argument, return a square matrix with ## the dimension specified. When called with more than one scalar argument the ## first two arguments are taken as the number of rows and columns and any ## further arguments specify additional matrix dimensions. The size may also ## be specified with a vector of dimensions @var{sz}. ## ## If no size arguments are given then the result matrix is the common size of ## @var{v} and @var{p}. ## @end deftypefn ## Author: KH <Kurt.Hornik@wu-wien.ac.at> ## Description: Random deviates from a discrete distribution function rnd = discrete_rnd (v, p, varargin) if (nargin < 2) print_usage (); endif if (! isvector (v)) error ("discrete_rnd: V must be a vector"); elseif (! isvector (p) || (length (p) != length (v))) error ("discrete_rnd: P must be a vector with length (V) elements"); elseif (any (isnan (p))) error ("discrete_rnd: P must not have any NaN elements"); elseif (! (all (p >= 0) && any (p))) error ("discrete_rnd: P must be a nonzero, non-negative vector"); endif if (nargin == 2) sz = size (v); elseif (nargin == 3) if (isscalar (varargin{1}) && varargin{1} >= 0) sz = [varargin{1}, varargin{1}]; elseif (isrow (varargin{1}) && all (varargin{1} >= 0)) sz = varargin{1}; else error ("discrete_rnd: dimension vector must be row vector of non-negative integers"); endif elseif (nargin > 3) if (any (cellfun (@(x) (! isscalar (x) || x < 0), varargin))) error ("discrete_rnd: dimensions must be non-negative integers"); endif sz = [varargin{:}]; endif rnd = v(lookup (cumsum (p(1:end-1)) / sum (p), rand (sz)) + 1); rnd = reshape (rnd, sz); endfunction %!assert (size (discrete_rnd (1:2, 1:2, 3)), [3, 3]) %!assert (size (discrete_rnd (1:2, 1:2, [4 1])), [4, 1]) %!assert (size (discrete_rnd (1:2, 1:2, 4, 1)), [4, 1]) ## Test class of input preserved %!assert (class (discrete_rnd (1:2, 1:2)), "double") %!assert (class (discrete_rnd (single (1:2), 1:2)), "single") ## FIXME: Maybe this should work, maybe it shouldn't. #%!assert(class (discrete_rnd (1:2, single(1:2))), "single") ## Test input validation %!error discrete_rnd () %!error discrete_rnd (1) %!error discrete_rnd (1:2,1:2, -1) %!error discrete_rnd (1:2,1:2, ones (2)) %!error discrete_rnd (1:2,1:2, [2 -1 2]) %!error discrete_rnd (1:2,1:2, 1, ones (2)) %!error discrete_rnd (1:2,1:2, 1, -1) ## test v,p verification %!error discrete_rnd (1, ones (2), ones (2,1)) %!error discrete_rnd (1, ones (2,1), ones (1,1)) %!error discrete_rnd (1, ones (2,1), [1 -1]) %!error discrete_rnd (1, ones (2,1), [1 NaN]) %!error discrete_rnd (1, ones (2,1), [0 0])