[R] Constrained vector permutation

[Jason Smith]

> It wouldn't be guaranteed to produce any usable permutation, but it seems
> like it would be much faster and so could be repeated until an acceptable
> vector is found.  What do you think?
>
> Thanks--
> Andy
>

I think I am not understanding what your ultimate goal is so I'm not
sure I can give you appropriate advice.  Are you looking for a single
valid permutation or all of them?

Since that constraint sets a ceiling on each subsequent value, it
seems like you could solve this problem more easily and quickly by
using a search strategy instead of random sampling or generating all
permutations then testing.  The constraint will help prune the search
space so you only generate valid permutations.  Once you are examining
a particular element you can determine which of the additional
elements would be valid, so only consider those.

--jason