R help - Nov 2008 - Command line arguments with source() - Windows OS

Hi Everyone,

I am pretty new to R and so far have mostly been using R interactively
through the Windows console.

I'm starting to write some scripts, and have been executing them using the
source() command, i.e. source(myRfile.R).

My questions is how can I pass command line arguments to R.  My file
"myRfile.R" has some global variables which I would like to be able to
set
at run-time, without having to go in and edit the text of the file each time
I want to run it.

I can't seem to find much information on this topic for Windows and using it
with the console - so any help would be greatly appreciated.

Thanks so much!

	[[alternative HTML version deleted]]

Brigid Mooney wrote:
> Hi Everyone,
>
> I am pretty new to R and so far have mostly been using R interactively
> through the Windows console.
>
> I'm starting to write some scripts, and have been executing them using
the
> source() command, i.e. source(myRfile.R).
>
> My questions is how can I pass command line arguments to R.  My file
> "myRfile.R" has some global variables which I would like to be
able to set
> at run-time, without having to go in and edit the text of the file each
time
> I want to run it.
>
> I can't seem to find much information on this topic for Windows and
using it
> with the console - so any help would be greatly appreciated.
This is the same on all platforms, Windows isn't special.

When you use source(), any variables currently defined in the R session 
will be visible to your script.  There is no "command line" needed, 
because you're executing the R code in the same session.

So you could do this:

paramValue <- 10
source("myRfile.R")

paramValue <- 15
source("myRfile.R")

The quotes are necessary, because source(myRfile.R) would go looking for 
a variable named myRfile.R, rather than using "myRfile.R" as the
filename.

Duncan Murdoch

Duncan Murdoch wrote:
>
> paramValue <- 15
> source("myRfile.R")
>
> The quotes are necessary, because source(myRfile.R) would go looking
> for a variable named myRfile.R, rather than using "myRfile.R" as
the
> filename.
why?

vQ