MATLAB: Choose elements, matrix with fewer elements

matrixrandomsize;

Hi Everyone,
I have two matrices of unknown size and I wish to choose all the elements of the smaller matrix and 'n' random elements from the larger matrix, where 'n' is the length of the smaller matrix. I also do not want to reuse indices when doing the random selection. Could you please teach me how to do this most efficiently?
Thank you!

Best Answer

function y = myFun(a,b)
   aN = numel(a);
   bN = numel(b);
   % Make sure a is smaller
   if aN>bN
      temp = b;
      b = a;
      a = temp;
      temp = bN;
      bN = aN;
      aN = temp;
   end
   i = randperm(bN)';
   y = [a(:);b(i(1:aN))];
end
Related Question