[R] workspace vs. image

[Thomas Lumley]

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