Re: [Help-glpk] optimizing my ilp, stopping overlapping of tiles

[Andrew Makhorin]

> I have a tiling problem that I've formulated as an ILP.

There is a more appropriate forum to discuss such things:
http://groups.google.com/group/sci.op-research/

Although, probably, some one on this list can help you.

> var x {p in POSITIONS, d in TILES, o in ORIENTATION} >= 0, <= 1,integer;

In MathProg you can use the keyword 'binary', i.e.

var x {p in POSITIONS, d in TILES, o in ORIENTATION}, binary;

> I couldn't find a way to say that a set was a union of a number of
> other sets. Is this possible, does it sound reasonable?

Yes, this is possible. For example:

set U := A union B union C;

>  If I say that 
>   set T := a b c z
>   set V := w x y z
> is the z in T and V the same if I use it as an index?

Yes, z is the same element in T and V.


Andrew Makhorin