How do I get a cumulative sum using cumsum in MATLAB?

Question

This is code

for i = 1 : 5
    b = i;
    a=cumsum(b);

end

fprintf(\'%f \\n\', a);

I expected 1 + 2 + 3 + 4 + 5 = 15 so I would print 15 at t

Answer 1

This is not how cumsum works. It takes the cumulative sum of an array the example below may explain better

a = 1:5;
b = cumsum(a); % b = [1, 3, 6, 10, 15]
c = sum(a) % add up all the elements c = 15

Does that help?