[R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread David Vonka
Hello, is it possible to do something like DATA - read.table(file=blabla.dat,subset=(sex==male)), i.e. make R read only a subset of a csv file ? I think it would be useful in case of very big datasets, but I can't find such a feature. Thanks for an answer, David Vonka

Re: [R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread Gabor Grothendieck
You can use pipe with read.table as in: http://tolstoy.newcastle.edu.au/R/help/06/02/20379.html Also note skip= and nrows= arguments to read.table. On 7/12/06, David Vonka [EMAIL PROTECTED] wrote: Hello, is it possible to do something like DATA -

Re: [R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread Roger Peng
It's not so straightforward as that, but you could construct something with readLines(). -roger On 7/12/06, David Vonka [EMAIL PROTECTED] wrote: Hello, is it possible to do something like DATA - read.table(file=blabla.dat,subset=(sex==male)), i.e. make R read only a subset of a csv file ?

Re: [R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread Prof Brian Ripley
On Wed, 12 Jul 2006, David Vonka wrote: Hello, is it possible to do something like DATA - read.table(file=blabla.dat,subset=(sex==male)), i.e. make R read only a subset of a csv file ? I think it would be useful in case of very big datasets, but I can't find such a feature. No. It

Re: [R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread bogdan romocea
It's possible and straightforward (just don't use R). IMHO the GNU Core Utilities http://www.gnu.org/software/coreutils/ plus a few other tools such as sed, awk, grep etc are much more appropriate than R for processing massive text files. (Get a good book about UNIX shell scripting. On Windows you

Re: [R] Is it possible to only read a subset by read.table ?

2006-07-12 Thread Steve Miller
You could also use Perl/Python/Ruby to pipe the data to R, e.g. msci - read.table(pipe(python /steve/python/msciintl.py),sep=,,header=T, as.is=T) This is a very reasonable way to exploit the data munging capabilities of the agile languages. Of course, better still is to query the data into R from