Re: [Help-glpk] Transport Problem advanced

[Andrew Makhorin]

> But if I leave out the impossible combinations of supply & demand varcost =
> "-1" I get always
> following errormessage:
> "no value for varcost[1,10]"

> ( x[i,j] is the solution quantity for combination )

> This is my current reading process:

> param supply{i in I};
> ...sql...
> I <- [INo], supply ~ count;

> param demand{j in J};
> ...sql...
>  J <- [JNo], demand ~ min_count;

> param varcost{i in I, j in J};
> ...sql...
> [ INo, JNo ], varcost ~ cost;

> Excuse me, I don't  know, what you mean - I'm a Beginner with glpk.

> Or, is there a switch to ignore empty combinations?

You can declare varcost as follows:

param varcost{i in I, j in J}, default -1;

In this case if a value for some varcost[i,j] is not provided, it
will be set to -1.