I've been watching with interest on this one. I've had problems with looping a randomForest procedure within R, and despite heroic efforts by the R developers this problem hasn't been solved.

I was thinking that if I could loop through the data extraction (from a MySQL) in the system, then call R inside the loop with the new data, and append a file with the results.

Does this seem feasible?

On Aug 6, 2004, at 1:22 AM, Prof Brian Ripley wrote:

The C stdin is used *always* to read commands from on Unix R, and even on
console versions stdin() is where the commands are read from.


R CMD BATCH is approximately giving you

R --vanilla --slave < my.R

and piping to such a command is going to do nothing for you.
Your command read.table(stdin() ... is going to read from the script my.R.


On Thu, 5 Aug 2004, Hayashi Soichi - shayas wrote:

I have asked this question before and Aaron J. Mackey and Tony Plate gave me
some great insight but I still can't figure out how to do what I am trying
to accomplish. So let me ask again...


What I am trying to do is to make R read data from pipe (stdin).

Say I have following files on my directory

my.dat
       apple 1
       orange 2
       grape 3

my.R
       d <- read.table( stdin(), header=F, dec='.',
col.names=c("name","type"), na.strings=c("xxxx"))
       summary(d)

and When I run this command

       cat my.dat | R CMD BATCH --vanilla --slave my.R

I am expecting to see the summery report for the datasource my.dat

But here is what I actually see in my.Rout
        > d <- read.table( stdin(), header=F, dec='.',
col.names=c("name","type"), na.strings=c("xxxx"))
        0: summary(d)
        1: proc.time()
        2: Error in scan(file = file, what = what, sep = sep, quote = quote,
dec = dec,  :
        line 1 did not have 2 elements
        Execution halted

If I execute the content of the my.R on regular R command line, I can
actually "type in" all datasource and creates the correct summery report. So
I don't know why I can make R to read the input from the piped datasource...

See the above analysis. What I don't know is why you expected this to
work: did you look at the sources, e.g. the file BATCH? If not - `great
insight' - the sources are the definitive documentation.


--
Brian D. Ripley,                  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

______________________________________________
[EMAIL PROTECTED] 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



______________________________________________ [EMAIL PROTECTED] 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

Reply via email to