Hi Johann On Thu, Mar 5, 2009 at 6:28 AM, johannct <[email protected]> wrote: > > Hello, > here is for the background : http://en.wikipedia.org/wiki/Lane-Emden_equation > and indeed checking for n=1 that sin(x)/x is a solution : > In [16]: diff(sin(x)/x, x,2)+2/x*diff(sin(x)/x,x)+sin(x)/x > works like a charm.
Excellent! > > But: > In [14]: dsolve(f(x).diff(x, x)+2/x*f(x).diff(x)+f(x),f(x)) > Out[14]: > C₁⋅sin(x sqrt(3)) + C₂⋅cos(x⋅sqrt(3) ) > Obviously I am doing something wrong... Unfortunately, our dsolve solver is not very advanced now. If you'd like to enhance it, so that it works for your equation above, it'd be awesome. Feel free to ask if you have any questions. Also please report the above as a bug into our bug tracker, as we need to fix it in any case. > > Thanks for your help. I just downloaded sympy using git, so I have > In [3]: sympy.__version__ > Out[3]: '0.6.4.beta1' > > best, and kudos for the great package, Thanks for using it, Ondrej --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
