Working ODE codes in R is very similar to MATLAB. 1st, to install
odesolve in R, type the following.

install.packages("odesolve")

Then choose a download mirror so it installs the package. Now that
it's in the R package in your computer, you can type the following to
load it on the current session.

library(odesolve)

Now you can access lsoda() which is the function used for solving
ODEs. R has a nice example in the help file in ?lsoda. At the minimum,
the user has to define 4 things:

1. initial values
2. the ODEs themselves
3. at which time points are they evaluated (for ODEs the values of t
don't matter.. only the length of the iterations)
4. parameter values

Then there are some other stuff that one may specify to help in the computation.

1. specifying the Jacobian (derivatives) of the ODEs that speed up
computations and so R doesn't have to approximate
2. tolerance levels to see how accurate the results should be (usually
about 1e-4)
3. maximum step size so R doesn't overshoot solutions and slow down
the computations


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Next -- please see Sec. 13 of the lab manual.  Downloading and sourcing DMBpplane.R will give you access to superb tools for ODEs.