Short addendum:
if using package simecol and given that a model object is called
"mymodel", then set:
solver(mymodel) <- "lsoda"
or:
solver(mymodel) <- "ode"
because "lsoda" it is the preferred default method of "ode".
Assigning:
solver(mymodel) <- "rk"
sets the default rk-Method "ode45" with adaptive step size. If you want
to use any other method not recognised by simecol, or if you want to
modify any defaults (e.g. tolerances) you can do it like this:
solver(mymodel) <- function(init, times, func, parms, ...)
ode(init, times, func, parms, ..., method = rkMethod("rk78dp"))
ThPe