sort array, apply rearrangement to second

[Victor Eijkhout]

I have two arrays, made with numpy. The first one has values that I want
to use as sorting keys; the second one needs to be sorted by those keys.
Obviously I could turn them into a dictionary  of pairs and sort by the
first member, but I think that's not very efficient, at least in space,
and this needs to be done as efficiently as possible.

I could use a hand.

Victor.
-- 
Victor Eijkhout -- eijkhout at tacc utexas edu