From Mark.Bravington@csiro.au Fri May 23 01:09:55 2003
Subject: RE: [Rd] Samples of external code with various compilers?
From: <Mark.Bravington@csiro.au>
Date: Fri, 23 May 2003 15:09:55 +1000
--------
Hi Duncan

Just a note about your R/Delphi page, in the 'Debugging' section. The
strategy that's suggested there doesn't allow control over where R
starts (RGUI anyway)-- it will start in the Projects/Options/Output
directory. Since my entire way of working in R depends on starting in a
fixed directory every time-- rarely the one in P/O/Output-- this caused
me no end of problems until I figured out a workaround a year or so ago.
The workaround is still OK in R1.6.2-- haven't checked it in 1.7.0 yet.
<<start>> means "the directory you want R to effectively start in".

(1) In Run/Parameters/Parameters, set

R_USER=<<start>> R_PROFILE=<<start>>\.R_PROFILE

Use single backslashes throughout.

(2) Make sure there's a .R_PROFILE file in <<start>> containing the code
below, which changes directory and sets up environment variables. Your
.First in <<start>> will execute normally after this.

setwd( '<<start>>')
local(
  if( file.exists( '.Renviron')) {
    enviro <- scan( '.Renviron', what=list( names='', .Data=''), sep='=')
    enviro <- do.call( 'structure', enviro)
    do.call( 'Sys.putenv', as.list( enviro))
  }
)

(3) When you launch R via Run/Run, you have to press F9 three times at
breakpoints which mysteriously appear in the CPU window. Dunno why.
Thereafter all is normal.

It seems (or seemed) necessary to do all of this in order to ensure that
all environment variables are set works and that .First is executed. I
must admit I haven't recently tried to see whether it can be simplified,
because it works OK for me. It does seem necessary to specify R_PROFILE
and to give a full path for it.

This might not work if you use a system-wide .Rprofile, but I *think* it
should still work if you have a "local" .Rprofile in <<start>> (note
that this one calls .R_PROFILE not .Rprofile). I don't use either,
preferring to rely on .First. It's probably possible to modify the
.R_PROFILE above to duplicate the normal procedure for executing a
system-wide .Rprofile, provided that the latter isn't normally specified
through the R_PROFILE environment variable itself.

More generally, it might be handy if RGUI (and I guess RTERM) had a
"startin" option that would allow them to run as if started in the
specified different directory. Probably Delphi etc. should just offer
that as a field, but it is simpler to change R than to change Delphi!
Easy for me to say that, of course-- I wouldn't actually have to do
it...

atb
Mark

*******************************

Mark Bravington
CSIRO (CMIS)
PO Box 1538
Castray Esplanade
Hobart
TAS 7001

phone (61) 3 6232 5118
fax (61) 3 6232 5012
Mark.Bravington@csiro.au