it seems that sage passes to Maxima something like
ic2('y(x)= %k1*sin(2*x)+%k2*cos(2*x),x = 0,'y(x) = 0, D[0]y(0) = 0)and it seems that maxima expects something like ic2(y= %k1*sin(2*x)+%k2*cos(2*x),x = 0,y = 0, anything = 0) Does this help? Robert On 3 říj, 16:22, Marshall Hampton <hampto...@gmail.com> wrote: > 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 -~----------~----~----~----~------~----~------~--~---
