[Gretl-users] matrix indexes question after sort

[Riccardo (Jack) Lucchetti]

On Thu, 24 Apr 2008, Allin Cottrell wrote:

> On Thu, 24 Apr 2008, Franck Nadaud wrote:
>
> See if this does what you're looking for:
>
> <script>
> matrix xc = X_COORD
> matrix yc = Y_COORD
> scalar n = rows(xc)
> scalar m = 4
> matrix nnlist = zeros(n,m)
> matrix idx = transp(seq(1,n))
> scalar xi, yi
>
> loop i = 1..n --quiet
>    xi = xc[$i,1]
>    yi = yc[$i,1]
>    dist = sqrt((xc-xi).^2 + (yc - yi).^2) ~ idx
>    xind = msortby(dist,1)
>    nnlist[i,] = transp(xind[2:m+1,2])
> end loop
>
> print nnlist
> </script>

Doh! I'd forgotten about msortby! Either gretl it's getting too big or I'm 
getting too old! Or perhaps both :-)


Riccardo (Jack) Lucchetti
Dipartimento di Economia
Università Politecnica delle Marche

r.lucchetti at univpm.it
http://www.econ.univpm.it/lucchetti