Re: Re : [Help-glpk] Assign a param to a set in data section

[Andrew Makhorin]

> Yes, this exactly what I need, Thanks.
> One exception maybe, from the documentation they say that this only works
> for param specified in the tabbing format and I would like it for any type
> of param, matrix type in my case.
> Is it still possible?

Do you mean something like this?

param : S : a :    j1 j2 j3 :=
                i1  1  .  3
                i2  4  5  . ;

No, such a feature is not implemented. (Afaik, in AMPL it is also
impossible to do that.)

If the domain is not very big, you can construct it in the following
way:

param a{i in I, j in J}, default 333333;

set S := setof{i in I, j in J: a[i,j] != 333333} (i,j);

where 333333 should be replaced by a value which is not appear in the
parameter data.

(Probably, there must be a built-in function, say dom(x), which
returns the domain set for x.)