Sorry. This is still unclear to me.
I generated a file called "Test.R" that contains the following lines:
commandArgs(TRUE)
cat("\n A = ",A,"\n")
cat("\n B = ",B,"\n")
cat("\n C = ",C,"\n")
First of all I have to clarify which command line we are talking about.
If I run the command "Rscript" from a Windows terminal, the system does not
recognize such a command:
C:\Documents and Settings\Monville\Utilities-Dir>Rscript Test.R aa bb cc
"Rscript" non รจ riconosciuto come comando interno o esterno,
un programma eseguibile o un file batch.
The above system response tells me that Rscript is not recognized either as an
internal or external command, an executable or a batch file.
In fact Rscript is an R command. Nevertheless, I started an R session and tried
such a command from R console command line
and got the following:
> getwd()
[1] "C:/Documents and Settings/Monville/Utilities-Dir"
> Rscript Test.R aa bb cc
Error: unexpected symbol in "Rscript Test.R"
I feel I do not have a good grasp of how to run R scripts the same way as I
usually run C programs.
Any help is welcome.
Thank you.
Maura
-----Messaggio originale-----
Da: Duncan Murdoch [mailto:murd...@stats.uwo.ca]
Inviato: mar 17/02/2009 17.34
A: mau...@alice.it
Cc: r-h...@stat.math.ethz.ch
Oggetto: Re: [R] R scripts and parameters
On 2/17/2009 10:55 AM, mau...@alice.it wrote:
> A couple of weeks ago I asked how it is possible to run an R script (not a
> function) passing some parameters.
> Someone suggested the function "commandArgs()".
> I read the on-line help and found no clarifying example. Therefore I do not
> know how to use it appropriately.
> I noticed this function returns the pathname of the R executable which is not
> what I need.
>
> I meant to ask if it is possible to open an R session and launch a script
> passing parameters that the script can retrieve and use itself.
> Just like in C I can run a program and call it with some arguments
>
>> Example_Prog A B C
>
> The program "Example_Prog" can acess its own arguments through the data
> structures "argc" an "argv".
>
> How can I launch an R script simulating the above mechanism ?
> Shall I use source ("script-name") ?
> Where are the arguments to be passed, as part of the source call ?
> Is the function "commandArgs" to be places as one of the first code lines of
> the script in order to access its own arguments ?
> Is there any "commandArgs" usage example ?
Gabor gave you a solution from within R. If you want to run a script
from the command line, then use commandArgs(TRUE). For example, put
this into the file test.R:
commandArgs(TRUE)
(The TRUE says you only want to see the trailing arguments, not
everything else on the command line.)
Then from the command line, do
Rscript test.R A B C
and you'll see the output
[1] "A" "B" "C"
Duncan Murdoch
tutti i telefonini TIM!
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