R help - Jul 2004 - More on global environment

To follow up on my previous question, suppose a user R session wants to 
unload one workspace and load another within an R session.  Is the 
following the correct sequence?

1.  save.image() to save the current workspace as .Rdata in the current 
working directory.
2.  rm(list=ls()) to remove everything from the workspace.
3.  setcwd("xxx") to set the new working directory.
4.  load(".Rdata") to load the new workspace.


-- 
Michael Prager, Ph.D.
NOAA Center for Coastal Fisheries and Habitat Research
Beaufort, North Carolina  28516
http://shrimp.ccfhrb.noaa.gov/~mprager/

That seems reasonable, although you might use

rm(list = ls(all.names = TRUE))

if you are interested in removing objects whose names begin with a period.

-roger

Mike Prager wrote:
> To follow up on my previous question, suppose a user R session wants to 
> unload one workspace and load another within an R session.  Is the 
> following the correct sequence?
> 
> 1.  save.image() to save the current workspace as .Rdata in the current 
> working directory.
> 2.  rm(list=ls()) to remove everything from the workspace.
> 3.  setcwd("xxx") to set the new working directory.
> 4.  load(".Rdata") to load the new workspace.
> 
>

I've posted the following to R-help before.  Hope it helps you.

cd <- function(dir = tclvalue(tkchooseDirectory()), saveOld=FALSE,
               loadNew=TRUE) {
    stopifnot(require(tcltk))
    if (saveOld) save.image(compress=TRUE)
    setwd(dir)
    rm(list=ls(all=TRUE, envir=.GlobalEnv), envir=.GlobalEnv)
    if (loadNew && file.exists(".RData")) {
        loaded <- load(".RData", envir=.GlobalEnv)
        return(invisible(loaded))
    }
}

[The tcltk part is based on Prof. Fox's help.]

Andy
> From: Mike Prager
> 
> To follow up on my previous question, suppose a user R 
> session wants to 
> unload one workspace and load another within an R session.  Is the 
> following the correct sequence?
> 
> 1.  save.image() to save the current workspace as .Rdata in 
> the current 
> working directory.
> 2.  rm(list=ls()) to remove everything from the workspace.
> 3.  setcwd("xxx") to set the new working directory.
> 4.  load(".Rdata") to load the new workspace.
> 
> 
> -- 
> Michael Prager, Ph.D.
> NOAA Center for Coastal Fisheries and Habitat Research
> Beaufort, North Carolina  28516
> http://shrimp.ccfhrb.noaa.gov/~mprager/
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
>

You may want to look at the notes on and functions for workspace
management that guide me. They can be downloaded from

http://faculty.washington.edu/lunnebor/Stat342/

by checking on "Exercises." I use the .GlobalEnv (position 1 on search
path) solely for scratch and have project work attached further down the
path. The two functions move() and rm.sv() contributed by my colleague
John Miyamoto and described in the above make this easy to do.

Michael Prager wrote:

: Date: Thu, 15 Jul 2004 14:45:41 -0400
: From: "Mike Prager" <Mike.Prager at noaa.gov>
: Subject: [R] More on global environment
: To: R Help list <r-help at stat.math.ethz.ch>
: Message-ID: <6.1.0.6.2.20040715143759.01e91668 at hermes.nos.noaa.gov>
: Content-Type: text/plain; charset="us-ascii"; format=flowed
:
: To follow up on my previous question, suppose a user R session wants
to
: unload one workspace and load another within an R session.  Is the
: following the correct sequence?
:
(snip)
: Michael Prager, Ph.D.
: NOAA Center for Coastal Fisheries and Habitat Research
: Beaufort, North Carolina  28516
: http://shrimp.ccfhrb.noaa.gov/~mprager/


**********************************************************
Cliff Lunneborg, Professor Emeritus, Statistics &
Psychology, University of Washington, Seattle
cliff at ms.washington.edu