Hi Simon, On Thu, Nov 26, 2009 at 01:16:09AM -0800, Simon King wrote:
> > On Nov 26, 2009, at 12:35 AM, Florent Hivert wrote: > [...] > > I think this makes perfect sense...I'm actually surprised it's not > > implemented that way already. > > That's impossible. > > The whole point of InfinitePolynomialRing is that you do *not* know in > advance how many variables you will eventually need. Its main purpose > is to compute Groebner bases of so-called Symmetric Ideals, and during > such computation it may very well be that the number of variables > increases during computation. > > And then, as I mentioned in my previous post, there is the problem > that in some cases you will use only very few variables, although the > indices may be very large and, again, you don't know in advance *what* > indices you will need. This is why there is a non-default sparse > implementation. I don't understand why what you say here is an answer to the following sentence of mine: Is there a problem in Symmetric Ideals if you have unused variables ? > > > Though this could be improved by using a similar trick than doubling the > > > size of a list when appending element, I'm not sure that's what we want. > > > > I think this makes perfect sense...I'm actually surprised it's not > > implemented that way already. > > That's impossible. > Running to get my train... Cheers, Florent -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
