summation of array elements

I have an array of say 5 elements and I want to run a loop and find the cumulative sum till the ith iteration eg.

array if f=[1 2 3 4 5]

so in the first iteration sum should be 1,in the 2nd it should be 3,in the third it should be 6 and so on...

what is the most efficient way to do this?

thanks in advance:]

Answer 1

[Azzi Abdelmalek]

f=[1 2 3 4 5];
out=cumsum(f)

[Terry McGinnis]

this gives the sum of all the elements.I want it till the ith element when the loop is in the ith iteration..

[Azzi Abdelmalek]

k=3
out=sum(f(1:k))

%or you can make a for loop

s(1)=f(1);
for k=2:numel(f)
    s(k)=s(k-1)+f(k);
end

[Guillaume]

or just iterate over the cumsum

f = [1 2 3 4 5]
for s = cumsum(f)
  %do something with s
end

[Terry McGinnis]

this is what i needed.thanks