Re: [Help-glpk] Problem with min command

[Andrew Makhorin]

> Initially I wanted to detect the index of an array where the value is
> different of zero, you guys helped me suggested me the following
> command:
>
> param index1 := min{k in SCHEDULES: values[k] != 0} k;
>
> The problem arises because there are some cases where the whole array
> "values" has zero values, and the min command does not work, a message
> error is shown: 
> "min{} over empty set; result undefined
> MathProg model processing error"
>
> and for these cases a value of index=1 will help me a lot.
> Does anybody have some suggestions?

param index1 := if card(SCHEDULES) = 0 then 
                   0 
                else
                   (min{k in SCHEDULES: values[k] != 0} k);