[Help-gsl] Array sorting queries

[Joseph Wakeling]

Hello,

A few queries about the sorting functions in GSL.

I have a few different arrays which I need to sort, depending on what
they are, into either ascending or descending order.

Later on in the program, I will need to perform index-sorts on the same
arrays -- again, respectively in either ascending or descending order.

What bothers me is that I don't see, from the GSL manual, how to do this
effectively.  Sorting in ascending order is easy -- just use gsl_sort()
and gsl_sort_index() -- but there's no hint in the manual how to sort
arrays in _descending_ order.

I could of course use gsl_sort_largest() over the whole array but that
means having to assign a separate destination array and seems an
expensive solution...

Can anyone suggest a better solution?  (Apologies if I've missed
something in the manual.)

Thanks & best wishes,

    -- Joe