On Mon, Aug 17, 2009 at 6:29 AM, Harald Schilly<[email protected]> wrote: > > From the notebook's "report a problem" bugtracker: > > The conversion of a sage expression to maxima depends of the argument > order of previous defined functions. For example: > > var('x y t') > L=function('L', t, x, y) > m1=maxima(diff(L,t)) > L=function('L', x, y, t) > m2=maxima(diff(L,t)) > m2 delivers the wrong expression! > ---------- > var('x y t') > L=function('L', t, x, y) > m1=maxima(diff(L,t)) > L=function('L', x, y, t) > m2=maxima(diff(L,t)) > print m1 > print m2 > > expect result m1 in all cases, no matter of the argument order!!!
> > May be it is essential to solve this issue due to the fact that sage > uses maxima to solve differential equations. In this case changing the > operator sequence within L should not change the result. > > Note from me: This applies to 4.1 and I can confirm it in 4.1.1 This error stems from "D" to "diff" derivative conversion (unavoidable for using Maxima) and has been reported at http://trac.sagemath.org/sage_trac/ticket/6376 I will post, hopefully today, a new native implementation of "diff" derivative for Sage/pynac. This will provide a solution to this issue by avoiding the conversion. Cheers, Golam --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
