[R] Add vectors of unequal length without recycling?

Maingo maingo at protonmail.com
Wed Dec 13 06:41:06 CET 2017

I'm a newbie for R lang. And I recently came across the "Recycling Rule" when adding two vectors of unequal length.

I learned from this tutor [ http://www.r-tutor.com/r-introduction/vector/vector-arithmetics ] that:


If two vectors are of unequal length, the shorter one will be recycled in order to match the longer vector. For example, the following vectors u and v have different lengths, and their sum is computed by recycling values of the shorter vector u.

> u = c(10, 20, 30)

> v = c(1, 2, 3, 4, 5, 6, 7, 8, 9)

> u + v

[1] 11 22 33 14 25 36 17 28 39


And I wondered, why the shorter vecter u should be recycled? Why not just leave the extra values(4,5,6,7,8,9) in the longer vector untouched by default?

Otherwise is it better to have another function that could add vectors without recycling? Right now the recycling feature bugs me a lot.

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