R help - Jul 2018 - A couple of batch mode questions

Within R one can use source() to run a batch file of R commands, while R CMD
BATCH
and Rscript are run from the command line. Is this correct?

   Given these choices, when would I want to run a script within R using
source(), and when would it be better for me to run it from the command
line?

   Reading Appendix B.4 Scripting with R in R-info.pdf, ?Rscipt, and ?BATCH I
get the impression that 'R CMD BATCH' reads from a named file and writes
output to a named file and Rscript reads/writes to stdin/stdout using
redirection. What are the pros and cons of each? When (or why) would I
select one over the other?

TIA,

Rich

"Within R one can use source() to run a batch file of R commands, while R
CMD BATCH
and Rscript are run from the command line. Is this correct?"

Yes.

I think your query answers your query: You use Rscript when you want to use
R in the command environment, perhaps as part of an analytical pipeline;
and you source an R file when you want to work within R.

Cheers,
Bert



Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Wed, Jul 25, 2018 at 7:41 AM, Rich Shepard <rshepard at
appl-ecosys.com>
wrote:
>   Within R one can use source() to run a batch file of R commands, while R
> CMD BATCH
> and Rscript are run from the command line. Is this correct?
>
>   Given these choices, when would I want to run a script within R using
> source(), and when would it be better for me to run it from the command
> line?
>
>   Reading Appendix B.4 Scripting with R in R-info.pdf, ?Rscipt, and ?BATCH
> I
> get the impression that 'R CMD BATCH' reads from a named file and
writes
> output to a named file and Rscript reads/writes to stdin/stdout using
> redirection. What are the pros and cons of each? When (or why) would I
> select one over the other?
>
> TIA,
>
> Rich
>
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On Wed, 25 Jul 2018, Bert Gunter wrote:
> "Within R one can use source() to run a batch file of R commands,
while R
> CMD BATCH and Rscript are run from the command line. Is this correct?"
>
> Yes.
Bert,

   Thanks for confirming.
> I think your query answers your query: You use Rscript when you want to use
> R in the command environment, perhaps as part of an analytical pipeline;
> and you source an R file when you want to work within R.
   That's a given. Why would I prefer Rscript over R CMD BATCH, or
vice-versa? I did not see much difference between the two in their help
files.

Regards,

Rich