As previously decribed floating point arithmetic is not associative. Which means it is very easy for floating point models not to match even though they are performing the same arithmetic operations. In matlab we compare the results:

a = 0.1 + 0.2 + 0.3 ;
b = 0.1 + (0.2 + 0.3);

isequal(a, b)
> 0

a & b are not equal, they are a least significant bit out, when comparing floating point numbers it is common to allow this amount of tolerance. Matlab anonymous functions can be used to create a new isequal function which takes a tolerance value. Idea from Stackoverflow.

isequalAbs = @(x,y,tol) ( all(abs(x-y) <= tol ));
floating_point_tol = 1e-15;

isequalAbs(a, b, floating_point_tol)