Andrey, Check out the hg bundle attached to this ticket: http://trac.sagemath.org/sage_trac/ticket/1136
Bobby Moretti was implementing code for doing this transformation, but never finished due to a subtle bug in the transformation maps (he gets the right cubic but not the right maps). It's possible you'll find the above bundle useful (no clue). On Thu, May 22, 2008 at 1:04 PM, Andrey Novoseltsev <[EMAIL PROTECTED]> wrote: > > I tried to convert > 2*x*y^2 + 2*a5*t*x*y - x^2 + (2*a4 - 8*t^3)*x - 1, > where a4, a5, and t are some complex parameters (which I would like to > keep as undetermined parameters), to Weierstrass normal form using > Nagell's algorithm and was not quite successful since some steps near > the end do not finish in a reasonable time (i.e. a few minutes). It is > possible that I have done some mistakes, since I didn't really tested > my code yet, but Jacob Lewis told me that this algorithm isn't very > fast anyway. > > As far as I can tell, Sage can do this conversion using MAGMA, but > only over rational field. Can anyone recommend an efficient way of > doing such a conversion with symbolic coefficients? Or, perhaps, it is > already done and I just cannot find the proper function? > > Thank you! > Andrey > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ 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://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
