Yes, the parsing of output from maxima is currently pretty messed up. I think its fair to say that symbolic ODEs are a real weak point in Sage right now. I'm not sure when I will have enough time to devote to really fixing this; my main interest is in using them to teach and I am not an expert on the CAS side of things.
One place on trac this is addressed is: http://trac.sagemath.org/sage_trac/ticket/6479 but I think we need someone to do a total redesign at some point. -Marshall Hampton On Oct 3, 7:14 am, David Joyner <wdjoy...@gmail.com> wrote: > This is a known bug. Marshall and I tried to fix it during a SageDays in > Seattle but failed to figure out the magic in Robert Bradshaw's code > for desolve. I think it is "easy to fix for those who know how to fix it > easily", but that rules me out:-) > > On Sat, Oct 3, 2009 at 3:30 AM, ma...@mendelu.cz <ma...@mendelu.cz> wrote: > > > Dear sage users and developers > > > trying to solve y''+4y=0 with initial conditions y(0)=0 and y'(0)=0 > > > y=function('y',x) > > eq=diff(y,x,2)+4*y==0 > > desolve(eq,y,ics=[0,0,0]) > > > sage returns y(0)*cos(2*x) and not 0 > > > What is wrong? The help for the desolve command shows the same > > behavior on slighhtly more complicated example. I think that if I > > state initial condition at 0, then y(0) is known and I can use this > > knowledge and simplify answer - in my case into 0 > > > Thanks > > > Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
