[AMPL 2591] Re: ranking

> On Jun 12, 3:14 pm, Hans Mittelmann <mittelm...@...> wrote:
>
> > I have a single-index parameter of real numbers of length n and want
> > to generate another parameter of integers recording the reverse order
> > of the elements in the first parameter,
> > so smallest number gets a 1 in the new parameter and largest an n.
>
> Can't swear this is the fastest, but it works assuming that there are
> no ties.
>
> param x {1..n};  # original data
> param r {1..n} integer ;  # ranks
> set X ordered by interval (-Infinity, Infinity);
> let X := setof {i in 1..n} x[i];
> let {i in 1..n} r[i] := ord(x[i], X);
>
> /Paul