V_RNSUBSET choose k distinct random integers from 1:n M=(K,N) Inputs: K is number of disinct integers required from the range 1:N N specifies the range - we must have K<=N Outputs: M(1,K) contains the output numbers
0001 function m = v_rnsubset(k,n) 0002 %V_RNSUBSET choose k distinct random integers from 1:n M=(K,N) 0003 % 0004 % Inputs: 0005 % 0006 % K is number of disinct integers required from the range 1:N 0007 % N specifies the range - we must have K<=N 0008 % 0009 % Outputs: 0010 % 0011 % M(1,K) contains the output numbers 0012 0013 % Copyright (C) Mike Brookes 2006 0014 % Version: $Id: v_rnsubset.m 10865 2018-09-21 17:22:45Z dmb $ 0015 % 0016 % VOICEBOX is a MATLAB toolbox for speech processing. 0017 % Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html 0018 % 0019 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0020 % This program is free software; you can redistribute it and/or modify 0021 % it under the terms of the GNU General Public License as published by 0022 % the Free Software Foundation; either version 2 of the License, or 0023 % (at your option) any later version. 0024 % 0025 % This program is distributed in the hope that it will be useful, 0026 % but WITHOUT ANY WARRANTY; without even the implied warranty of 0027 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 0028 % GNU General Public License for more details. 0029 % 0030 % You can obtain a copy of the GNU General Public License from 0031 % http://www.gnu.org/copyleft/gpl.html or by writing to 0032 % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. 0033 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0034 if k>n 0035 error('rnsubset: k must be <= n'); 0036 end 0037 % We use two algorithms according to the values of k and n 0038 [f,e]=log2(n); 0039 if k>0.03*n*(e-1) 0040 [v,m]=sort(rand(1,n)); % for large k, just do a random permutation 0041 else 0042 v=ceil(rand(1,k).*(n:-1:n-k+1)); 0043 m=1:n; 0044 for i=1:k 0045 j=v(i)+i-1; 0046 x=m(i); 0047 m(i)=m(j); 0048 m(j)=x; 0049 end 0050 end 0051 m=m(1:k);