The differential equation solving engine of sympy is very limited right now. You can look in the dsolve function in the solvers file in the source to see what it can solve. It basically can solve linear, Bernoulli, and some special cases of first and second order equations. If I get accepted into the Google Summer of Code program, my project will be to expand it. See my application draft here: http://wiki.sympy.org/wiki/GSoC2009_Application_Template/Aaron_Meurer
Aaron Meurer On Mar 30, 2009, at 9:42 AM, comer.dun...@gmail.com wrote: > > I also meant to say that when one puts sin(t) instead of g(t) in the > dsolve, it still does not work. So, it seems clear that this just has > not been implemented (yet?). > > Comer > > On Mar 30, 11:40 am, "comer.dun...@gmail.com" <comer.dun...@gmail.com> > wrote: >> Hi, >> >> I have a need to have sympy solve the following second order >> differential equation for f(t) using dsolve: >> >> dsolve(f(t).diff(t,t) + f(t).diff(t) + mu**2 *f(t) - g(t) , f(t)) >> >> where mu is a constant and g(t) is at least twice differentiable. >> The >> homogeneous equation is easy enough with dsolve: >> >> dsolve(f(t).diff(t,t) + f(t).diff(t) + mu**2 *f(t) , f(t)) >> >> The result returned for the homogeneous equation seems correct but >> the >> pasting of the output into gmail produces a relatively ugly thing, >> character wise so I did not paste it here. >> >> So my issue is the general case. Now we know how in principle to go >> about doing this using the method of variation of parameters. It >> would be nice to have sympy do the right thing. >> >> I also note that this particular homogeneous equation does not have >> two distinct solutions but only one, due to the special selection of >> coefficients. So, the solve for the particular solution would have to >> handle this case too, so it would seem. >> >> Has anyone done this? Did I not do something above? >> >> Thanks. >> >> Comer > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
