Re: Re: Polynomial rewriting question
- To: mathgroup at smc.vnet.net
- Subject: [mg101610] Re: [mg101525] Re: Polynomial rewriting question
- From: Daniel Lichtblau <danl at wolfram.com>
- Date: Fri, 10 Jul 2009 23:25:05 -0400 (EDT)
- References: <200907090557.BAA17323@smc.vnet.net>
AndrewTamra wrote: > Thanks Daniel. You mentioned FullSimplify will SOMETIMES recognize the > factorization. Could you think of any other deterministic method/algorithm > I can implement in Mathematica for getting the simplification I am looking for? Not offhand. The biggest impediment is in "factoring". I used the term loosely, to mean ability to isolate x-y as a reasonable-to-use common subexpression (CSE). I should have chosen a different term because factoring, an algorithmic process, is quite well defined. > Even a probablistic numeric algorithm is OK as well, where I can test within > a reasonable probability, that there exists the factorization I am looking > for; similar to the fast probablistic algorithms for Ideal membership problem. Maybe I'm forgetting something important, but I'm not aware of fast probabalistic ideal membership algorithms. Regardless, I do not know a good way to deduce optimal CSEs, other than what you might find in CSE elimination literature. > That way, first I can quickly determine the existence of such a simplification; > then employ a slower (may be inefficient) algorithm to find the simplification > (t=x-y in the example) > > Thanks I think finding the simplification is the crux of the problem. You won't know one is there without explicitly finding it. Daniel
- References:
- Re: Polynomial rewriting question
- From: AndrewTamra <AndrewTamra@yahoo.com>
- Re: Polynomial rewriting question