MATLAB: VectorB(n) = sum(vectorA(1:n)) without a loop

loopMATLABsumvector

I would like to do:

vectorB(n) = sum(vectorA(1:n))

without a loop.

Thanks in advance

Perhaps you just want cumsum()

help cumsum
doc cumsum

Or you just need:

v= accumarray(n(:),n(:),[],@(x) sum(vectorA(1:x)));
Wanted = v(n);
% or
Wanted = arrayfun(@(x) sum(vectorA(1:x)),n)

w=[1 2; ...
   3 4; ...
   5 6];
N=5;
E=size(w,1);
F=size(w,2);
D=repmat(reshape(w',1,F,1,E),N,1,N,1);

Try this:

v = 1:n;
vs = cumsum(v)