We are going to use the BESIRK code to solve this particular problem. BESIRK is an implementation of a semi-implicit Runge-Kutta method (see Schwalbe et al, 1996) and is much faster than the methods built in to dsolve/numeric that we used in another example. We read the code into Maple.
Does anyone know where I can get this BESIRK code?
You need the ﬁles besirk and besirkhelp.mws, the latter shows how to set it up.
FYI: I am co-author of BESIRK.