Recycling Rule in R
Vectorized computations occur on most arithmetic operators we may encounter the problem of adding together two vectors of different lengths and some rule is needed to describe what will happen in that situation. This is often referred to as the recycling rule.
The recycling rule states that the shorter vector is replicated enough times so that the result has at least the length of the longer vector and then the operator is applied to the resulting elements, of that modified vector, that correspond to elements of the longer vector. If the shorter vector is not an even multiple of the longer vector, a warning will be signalled.
> 1:10 + 1:3  2 4 6 5 7 9 8 10 12 11