Re: [Help-glpk] Indexing a subset from 1..n

[glpk xypron]

Hello Joel,

param nPeriods := 12;
set Periods, default{1.. nPeriods};
# let even period be open
param FacilityOpen{p in Periods}, binary := if p mod 2 == 0 then 1 else 0;
set OpenPeriods:= setof{p in Periods: FacilityOpen[p] = 1}(p);
param nOpen := card(OpenPeriods);
set NOpen := {1..nOpen};
# beware this will take n^2 time
param pOpen{n in NOpen} := sum{p in OpenPeriods :
  n ==card(setof{i in OpenPeriods: i <=p }i) } p;
display pOpen;
end;

Best regards

Xypron
-------- Original-Nachricht --------
> Datum: Wed, 28 Nov 2012 08:15:46 +1100
> Betreff: [Help-glpk] Indexing a subset from 1..n

> Hello all,
> I have a set of Periods from which I create the subset OpenPeriods when
> the facility is open.
> param nPeriods;set Periods, default{1.. nPeriods};param FacilityOpen{p in
> Periods}, binary;set OpenPeriods:= setof{p in Periods: FacilityOpen[p] = 1}
>  (p);
> The facility is not open during all periods and I have a constraint that
> considers the configuration of the facility the previous time it was open.
> So I am trying to index the set of OpenPeriods from 1...card(OpenPeriods)
> rather than with p but so far without any luck.
> Any help would be much appreciated.
> Thanks,
> Joel