On Dec 5, 2007, at 10:46 AM, John Cremona wrote: >>> #1058 the mwrank interface barfs on bad input > > This is a triviality. mwrank_elliptic curves need to be initialized > with 5 integers, period. Currently Sage just tried to coerce the 5 > things to integers, whcih some stupid results (e.g. 1.2 gets rounded > to 1 with meaningless results). > > A more interesting issue is whether to allow mwrank_elliptic curves to > be initialised with rational (non-integral) data, since this makes > perfect mathematical sense and users regularly try it. This could be > solved in two ways: either by me in the C++ code -- which is not > trivial but might be good to do for the stand-alone mwrank program > too. Or by Sage converting to a minimal model (easy) and then > changing back the points afterwards to the original model (also easy). > Both of these should be done as part of the plan to implement > model-changing maps (i.e. [u,r,s,t] transformations for those who know > what those are) which I rashly thought I would do months ago (see > ticket #740).
I actually implemented model-changing maps as part of the new gp- simon code patch, so this should be trivial to wrap on the Sage side of things. - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
