[R] Usage questions

[Paul Johnson]

Can I ask a couple of usage questions?  (RedHat Linux 6.1, R-1.1)

1. This may just indicate I'm a dinosaur who can't leave SAS behind.  I
want to write programs and run them with source() to see what they do,
then I would like to use the "up arrow" to go back through the commands
that were in the file, fiddle them, see what they do, and so forth.  Is
there no way?  SAS has a functionality of a "program editor" screen
where you can fiddle a  file, run it, then save it when it is the way
you want. But in R I don't get any command history with source(), so I
can't experiment with commands.

2. What does it mean when output from a command is just
NULL

It seems like everything is OK when this happens, but it does not always
happen.

3.  When I tried
>  postscript(file="test3.ps",onefile=FALSE)

And then I ran some models, it did not create several files.  Where did
I go wrong? I'm reading the postscript help page and it seems like
there's something missing, or I'm illiterate, or both:

   postscript(file = ifelse(onefile, "Rplots.ps", "Rplot
                onefile = TRUE,
                paper, family, bg, fg, width, height, horizontal,
pointsize,
                pagecentre, print.it, command))

The first line does not appear to be complete.
-- 
Paul E. Johnson                       email: pauljohn at ukans.edu
Dept. of Political Science            http://lark.cc.ukans.edu/~pauljohn
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66045                FAX: (785) 864-5700
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._