Re: [Help-glpk] Problem with min command

[Andrew Makhorin]

> > Right now the code I have is the following, and the same error is
> > presented:
> > 
> > set SCHEDULES := 1..288 ;
> > 
> > param Temp {k in SCHEDULES} := if k=1 then TempIN_Meas[k] else 
> >           (if (TempIN_Meas[1]<TempSPDN[1] or
> > TempIN_Meas[1]>TempSPUP[1]) then (Temp[k-1] + 5*(BetaAC * ActLev[k] +
> > OutTemp[k]*GamaAC))/(1+5*GamaAC));
> > 
> > param index {k in SCHEDULES} := if (Temp[k]<TempSPDN[k] or
> > Temp[k]>TempSPUP[k]) then 0 else k;
> > 
> > param index1 := if card(SCHEDULES) = 0 then 1 else (min{k in
> > SCHEDULES: index[k] != 0} k);
> > 
> 
> Hmm... Try the following:
> 
> param index1 := if card(SCHEDULES) = 0 then 1 else 
> (min{k in (SCHEDULES union { 0 }): index[k] != 0} k);

Don't try. The following code works:

   set S := { 1, 2, 3 };

   set T := { };

   display if card(S) = 0 then 0 else (min{k in S}k);

   display if card(T) = 0 then 0 else (min{k in T}k);

so your code also should work. Which the error message did you get?