This took me a while. I tried doing a batch job (based on an example) that used postscript function to create a postscript file. Natutally, the function could not be found. I googled about for almost an hour. There is a lot of useful information about R on the web. But there is very little debugging help when just getting started.
I think that part of the problem is that I installed R manually. The Ubuntu Package Manager did not have R. Today, I was reminded of the Synaptic Package Manager and that had a lot of r-cpan stuff which I had not downloaded (nor seen). I found an r-base and r-base-core. The r-base had not been installed, so I installed it and some other packages that looked important. The postscript function now works although I wish it had been a clean install.
Update: Another day, postscript not working. Tried to install Cairo and got some errors within R. It could not find cairo.h
Looking at my xterm history, I found