On Sunday, January 29, 2017 at 2:38:37 PM UTC, Martin Baker wrote: > > On 01/29/2017 01:41 PM, Dima Pasechnik wrote: > > Well, e.g. Todd-Coxeter is pretty much domain-specific; one could also > > choose to interface a stand-alone coset enumeration routine > > like ACE (see http://staff.itee.uq.edu.au/havas/ > > and https://gap-packages.github.io/ace/). Producing toy implementations > > of coset enumeration is of course fun, but is limited to (self)teaching > > purposes---I'm saying this as someone who uses coset enumeration in > > research quite a bit. > > Hi Dima, > > I'm sure the approach of gluing together mature implementations is very > powerful but if I wanted to work that way I think I would work with SAGE. > > I like the approach of having implementations richly interconnected and > written in a common language (SPAD) which is designed for mathematics > and is statically typed. > > I guess its good that both approaches exist and we can choose what is > best for each application. > > I also think it is good to introduce what you may consider toy > implementations. I assume most mature implementations must have started > small. If we took the above approach to its most extreme then would > anything ever be added to FriCAS? >
No, no, there are plenty of things out there that crying out to be implemented, or implemented efficiently---and FriCAS lends itself naturally to these problems, as it's not essentially pure combinatorics, but something mixed with nontrivial (non)-linear algebra. And you don't need to go far from coset enumeration: e.g. consider the problem of "vector enumeration" - constructing finite-dimensional representations of group modules given by generators and relations. See http://www.sciencedirect.com/science/article/pii/002437959390245J and http://www.sciencedirect.com/science/article/pii/S0747717108800958 (free downloads, IMHO). The only implementation I know, written in C by Steve Linton, is quite outdated and restricted in several ways. See https://github.com/gap-packages/ve for the source (I updated it a bit recently so that at least one can build it on modern Linux systems) Dima > Martin B > > > -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
