On Fri, Dec 4, 2009 at 11:50 AM, Sebastian Pop <seb...@gmail.com> wrote: > On Fri, Dec 4, 2009 at 10:39, Tobias Grosser <gros...@fim.uni-passau.de> > wrote: >> I do not believe this is already possible for arbitrary N. >> >> You would have to write a scattering function like this >> >> s0 = i+n*(j-1) >> >> What is >> >> s= i + n*j - n >> ^^^ Here is a product that is not affine linear. > > Yes this is affine linear, but not representable in the current way we > deal with parameters in the polyhedral model... Note that constant > times IV would be allowed, and yes parameters are named constants.
We usually call this case (parameter times IV) "fully parametric". Armin Grosslinger looked at it before finding a more general solution, it's not easy and typically it leads to a massive versioning :-/... >> There are extensions to the polytop model to make this possible, but >> they are not close to be production ready. > > I think that we should revisit this independently of general solutions. > >> Just recently I Armin Groesslinger gave a nice talk about this >> topic. If you want I can look for his work describing solutions. > > I also have discussed with Armin when I was visiting INRIA earlier > this year, and I know what he's working on. > > Sebastian >
