Home different results of mtimes() in MATLAB
 I tried belows on MATLAB. A = rand(2, 20); B = rand(20, 1); D1 = A * B; D1 = D1(1); D2 = A(1, :) * B; D1 == D2  ans = 0 D1 - D2  ans = -8.8818e-16 I expected that two results are the exactly same. What differences between both calc ways?.. Thanks,