solve nonlinear differential equations?
 

Hey, is there anything like Mathematica's NDsolve in an open-source program like Maxima or Sage?

I would like something where I can put the differential equation(s) directly into the function, without having to change it to break it into a system of first order ODEs.

Something like this? http://www.scicomp.uni-erlangen.de/a...W/diffequ.html
jdk