Mercurial > hg > camir-aes2014
annotate toolboxes/FullBNT-1.0.7/KPMstats/multirnd.m @ 0:e9a9cd732c1e tip
first hg version after svn
| author | wolffd |
|---|---|
| date | Tue, 10 Feb 2015 15:05:51 +0000 |
| parents | |
| children |
| rev | line source |
|---|---|
| wolffd@0 | 1 function r = multirnd(theta,k) |
| wolffd@0 | 2 %MULTIRND - Random vector from multinomial distribution. |
| wolffd@0 | 3 % r = multirnd(theta,k) returns a vector randomly selected |
| wolffd@0 | 4 % from the multinomial distribution with parameter vector |
| wolffd@0 | 5 % theta, and count k (i.e. sum(r) = k). |
| wolffd@0 | 6 % |
| wolffd@0 | 7 % Note: if k is unspecified, then it is assumed k=1. |
| wolffd@0 | 8 % |
| wolffd@0 | 9 % Author: David Ross |
| wolffd@0 | 10 % |
| wolffd@0 | 11 |
| wolffd@0 | 12 %-------------------------------------------------------- |
| wolffd@0 | 13 % Check the arguments. |
| wolffd@0 | 14 %-------------------------------------------------------- |
| wolffd@0 | 15 error(nargchk(1,2,nargin)); |
| wolffd@0 | 16 |
| wolffd@0 | 17 % make sure theta is a vector |
| wolffd@0 | 18 if ndims(theta) > 2 | all(size(theta) > 1) |
| wolffd@0 | 19 error('theta must be a vector'); |
| wolffd@0 | 20 end |
| wolffd@0 | 21 |
| wolffd@0 | 22 % if theta is a row vector, convert it to a column vector |
| wolffd@0 | 23 if size(theta,1) == 1 |
| wolffd@0 | 24 theta = theta'; |
| wolffd@0 | 25 end |
| wolffd@0 | 26 |
| wolffd@0 | 27 % make sure k is a scalar? |
| wolffd@0 | 28 |
| wolffd@0 | 29 % if the number of samples has not been provided, set |
| wolffd@0 | 30 % it to one |
| wolffd@0 | 31 if nargin == 1 |
| wolffd@0 | 32 k = 1; |
| wolffd@0 | 33 end |
| wolffd@0 | 34 |
| wolffd@0 | 35 |
| wolffd@0 | 36 %-------------------------------------------------------- |
| wolffd@0 | 37 % Main... |
| wolffd@0 | 38 %-------------------------------------------------------- |
| wolffd@0 | 39 n = length(theta); |
| wolffd@0 | 40 theta_cdf = cumsum(theta); |
| wolffd@0 | 41 |
| wolffd@0 | 42 r = zeros(n,1); |
| wolffd@0 | 43 random_vals = rand(k,1); |
| wolffd@0 | 44 |
| wolffd@0 | 45 for j = 1:k |
| wolffd@0 | 46 index = min(find(random_vals(j) <= theta_cdf)); |
| wolffd@0 | 47 r(index) = r(index) + 1; |
| wolffd@0 | 48 end |