> Re: [Help-glpk] help
>
> r (i) is a parameter and represents the resource request from the i-th
> activities by the system.
> The variable is x (i, t) where i is the index of the activities of the
> whole W and t is the index of the time interval.
> R is the total available resource is not exceeded while d (i) is the
> duration of the
i.th activity
>
> >
> >
> >
> >> On Tue, 26 Jun 2012, Daniele Micarelli wrote:
> >>
> >> I have to solve a linear programming problem with the language and I'm
> >>> planning mathprog
> >>> I have difficulty writing the following constraint: ΣΣ r (i) * x (i,
> t)
> >>> <= R
> >>> where the first summation is true for all belonging to the W and the
> >>> second
> >>> summation has as its lower end t-d(i) and upper bound as t-1
> >>>
> >>
> >> You've not made it clear what is a variable and what is not.
> >> If r and x are both variables, you are done.
> >> *Linear* programming does not involve products of variables.
> >>
> >> --