Sum every nth points

Question

I have a vector and I need to sum every n numbers and return the results. This is the way I plan on doing it currently. Any better way to do this?

Answer 1

One way is to convert your vector to a matric then take the column sums:

colSums(matrix(v, nrow=n))
[1]  55 155 255 355 455 555 655 755 855 955

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Just be careful: this implicitly assumes that your input vector can in fact be reshaped to a matrix. If it can't, R will recycle elements of your vector to complete the matrix.