Generalized Sorting

QUICKSORT allows the user to sort by any desired criteria. The user passes the data and a comparison function to the QUICKSORT and QUICKSORT returns an indexing vector sorted based on the comparison function.

The comparison function may be an inline function or a function handle. Function handles are an order of magnitude faster than inline functions. I use the TMP_HANDLE utility for creating temporary function handles in MATLAB 6.

QUICKSORT is implemented in m-code and uses a modified quicksort algorithm which sorts by "less than", "equal to" and "greater than". It is much slower than the builtin sort function, but also much more flexible.