Partitions the input data according to compFun, such that position k contains
the kth largest/smallest element according to compFun. For all elements e
with indices < k, !compFun(datak, e) is guaranteed to be true. For all
elements e with indices > k, !compFun(e, datak) is guaranteed to be true.
For example, if compFun is "a < b", all elements with indices < k will be
<= datak, and all elements with indices larger than k will be >= k.
Reorders any additional input arrays in lockstep.
Partitions the input data according to compFun, such that position k contains the kth largest/smallest element according to compFun. For all elements e with indices < k, !compFun(datak, e) is guaranteed to be true. For all elements e with indices > k, !compFun(e, datak) is guaranteed to be true. For example, if compFun is "a < b", all elements with indices < k will be <= datak, and all elements with indices larger than k will be >= k. Reorders any additional input arrays in lockstep.