Hi Pierre! On Oct 20, 2:44 pm, Pierre <[email protected]> wrote: > A priori, the two computations (one with I, one with J) are different.
Yes, probably I was confusing it with a different problem, namely to find just *some element* in the preimage of an element (if it exists), but not the complete preimage. Here, one has some fixed Groebner basis, and the computation of one element in the preimage is mainly a normal form computation. > (ii) add the functionality to SAGE : a lot of trouble as far as i'm > concerned. > > Hey if anyone wants to take me through the steps for (ii)... you > wouldn't believe how little i know. I guess the first step is to find the right location in the source. Does it seem natural to implement it as method of sage.rings.morphism.RingHomomorphism, since it is so generic? And then raise NotImplementedError if domain or image are unsuitable? Or is there a specialised class for homomorphisms of MPolynomialRing_libsingular? Then you should make a clone of sage, in order to not mess up your installation, e.g.: sage -clone my_work and edit the file, say SAGE_ROOT/devel/sage-mywork/sage/rings/morphism.pyx You can test your changes after doing sage -br (this is: build and run sage) If everything works, you produce a patch, ask William for a trac account, and submit your contribution. But I agree with Martin that the discussion should be moved to sage- devel. And there are also some pages in the developer's guide that might be worth reading. Cheers, Simon --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
