function tsamps = rubinstein_beta(alpha,beta,n)
% RUBINSTEIN_BETA - generate random variables according to a beta distribution 
% according to the method of Rubinstein
% 
% Input:
%   n: we generate a [1,n] array of random variables.
%
% Written by:
% -- 
% John L. Weatherwax                2008-02-20
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

indx=1; tsamps = zeros(1,n); 
while( indx<=n )
  y1 = rand(1,1)^(1/alpha);
  y2 = rand(1,1)^(1/beta); 
  if( y1+y2<=1 )
    tsamps(indx)=y1/(y1+y2); 
    indx=indx+1; 
  end
end