[R] sequential sum of a vector...

[William Revelle]

At 7:33 PM +0530 7/23/08, Shubha Vishwanath Karanth wrote:
>Hi R,
>Let,
>x=1:80
>I want to sum up first 8 elements of x, then again next 8 elements of x,
>then again another 8 elements..... So, my new vector should look like:
>
>c(36,100,164,228,292,356,420,484,548,612)
>I used:
>aggregate(x,list(rep(1:10,each=8)),sum)[-1]
>or
>rowsum(x,group=rep(1:10,each=8))
>But without grouping, can I achieve the required? Any other ways of
>doing this?
>
>Thanks, Shubha
>

colSums(matrix(x,nrow=8))

Bill

-- 
William Revelle		http://personality-project.org/revelle.html
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