Dear members 
In short, as indicated by the title, I was trying to combine 20 vectors into one new matrix i.e., 10 each generated by condition_A and condition_B using a for loop. Specifically, assigning all condition_As to the second column,  and all condition_Bs to the third column of a new matrix.
  for n = 1: 10        
        
        condition_a = [ repmat(23,1,6) repmat(99,1,6) ];
        condition_A = condition_a(randperm(length(condition_a)));
     
        
        condition_b = [111 112 127 123 211 218 221 222 311 312 321 333 ]; 
        condition_B = condition_b(randperm(length(condition_b)));
        
        
  end
I apologize if this is a naive question, thanks in advance.
Please let me know if more information is needed.