[R] Efficient way to substract all entries in two vectors from each other

[Johannes Graumann]

Hi all,

I'm to inexperienced to come up with the matrix solution elusively appearing
on the horizon for the following problem and would appreciate if you could
give me a nudge ...
I have two vectors a, and b and need to find the closest match for each
value of a in b.
How to do that efficiently?

Thanks, Joh