rather than Splus, then you will need to include one other command:

cd /group/dengue/xgobi
R
source("Rfunction") # note the use of Rfunction rather than Sfunction
source("scatmat.s")
source("state.x77")
where you must download the files state.x77, scatmat.s, and Rfunction.

If you have your file in a directory other than the xgobi directory, then you should add the path before the filename, e.g.

source("/usr/home/aelon/state.x77")