On 12 October 2014 21:26, Waldek Hebisch <[email protected]> wrote: > Bill Page wrote: >> >> There is some unpleasant code in DERHAM that presumes knowledge of the >> Rep of AntiSymm: >> >> terms : % -> List Record(k: EAB, c: R) >> terms(a) == >> -- it is the case that there are at least two terms in a >> a pretend List Record(k: EAB, c: R) >> >> I recall that this sort of thing was done elsewhere in some of the >> FriCAS code for polynomials but maybe it would be better to get rid of >> at least this case right now. What do you think? > > This looks like relatively easy to eliminate. OTOH AntiSymm > contains more such things. >
Yes. > Going directly to represetation makes sense if operation > can not be done otherwise or if there is significant > performance gain. In this case official inteface should > be enough. 'terms' is used for printing and should not > be performance critical. Concerning uses of representation > in AntiSymm I do not think that this is important, but > it would be good to have some timings. > Probably printing could be done using just leadingCoefficient, leadingBasisTerm and reductum. But it seems a little inconsistent to me that AntiSymm uses explicit exports to expose just reductum, leadingCoefficient and leadingBasisTerm. I think it might be better if AntiSymm included at least IndexedDirectProductCategory. Since the Rep of AntiSymm is FreeModule, IndexedDirectProductCategory could be easily satisfied and would provide these functions as well as 'listof Terms' which could replace the local function terms, thus eliminating the direct reference to the Rep. A more ambitious alternative might be to use FreeModuleCategory as is done by LeiPolynomial and XPolynomialRing. Bill Page. -- 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 http://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
