[R] workspace vs. image

[Iyue Sung]

Thanks for the reply Thomas, I think I (am starting to) understand.

But it appears that if I load, "C:\Program Files\R\Project1\.RData",
after starting in the directory "C:\Program Files\R\rw1060", 
R will save the objects I create in the current session in both
"C:~\Project1" and "C:~\rw1060".  

So, if all I really care about is making sure objects for 
projects are stored in different .RData files, why would it
matter which directory I start in? 

Thanks,
Iyue


> -----Original Message-----
> From: Thomas Lumley [mailto:tlumley at u.washington.edu]
> Sent: Wednesday, December 18, 2002 11:05 AM
> To: Iyue Sung
> Cc: R-help at stat.math.ethz.ch
> Subject: Re: [R] workspace vs. image
> 
> 
> On Wed, 18 Dec 2002, Iyue Sung wrote:
> 
> >
> > Hello [R]ians,
> >
> >   I'm hoping someone can clarify the difference between a 
> Workspace Image
> > and Working Directory.  I created a directory on my PC, say,
> 
> The workspace image is a file (containing an R workspace), the working
> directory is a directory
> 
> > "C:\Program Files\R\Project1" and then saved my objects in
> > "C:\Program Files\R\Project1\.Rdata".
> 
> Good.
> 
> > Then, in a subsequent session, I reloaded these objects using
> >
> > > load("C:/Program Files/R/Project1/.RData")
> 
> Yes.
> 
> > At first, I thought I was suppose to use
> >
> > > setwd("C:\\Program Files\\R\\Project1")
> >
> > and that R would automatically use "C:/Program 
> Files/R/Project1/.RData".
> > But this appears not to be the case.
> 
> No, because it's too late by then.
> 
> At startup R automatically looks for .RData in the directory 
> that it is
> started in, the initial working directory.  Changing the 
> working directory
> afterwards won't make a new .RData be loaded
> 
> To change which workspace is loaded at startup you need to change the
> directory R starts in.  The easiest way to do this under Windows is
> probably to make a number of different R shortcuts and set 
> the 'Start in'
> directory in the Properties tab of each one.
> 
> > I got this impression from Section 1.11 of "An Introduction 
> to R" which states
> > "...objects are written to a file called '.RData' in the 
> current directory".
> 
> Yes. The current directory when the writing or reading is happening.
> 
> > What "things" then, should go in the Workspace Image but 
> not the Working Directory
> > and vice versa (Plots?), and what am I not understanding?
> 
> R reads and writes everything in the current working 
> directory unless told
> otherwise.  I think you aren't understanding `current'
> 
> 
> 	-thomas
> 
> 
>