... for which you need ?connections and the "nrows" argument to read.table and friends.
(also ?scan and its "nlines" argument) -- Bert Gunter Genentech -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of jim holtman Sent: Friday, July 11, 2008 9:58 AM To: [EMAIL PROTECTED] Cc: r-help@r-project.org Subject: Re: [R] reading in a subset of a large data set If the data you want is contiguous, then just 'skip' the number of records and then read the number you want. If you want to select a random sample, then checkout http://article.gmane.org/gmane.comp.lang.r.general/78318/match=random+read In your case where you want to conditionally read based on values, then you may have to read in a subset, select the records you want and then continue reading the file. At then end, you can reconstruct the data into a single dataframe.` On Fri, Jul 11, 2008 at 12:25 PM, Stacey Burrows <[EMAIL PROTECTED]> wrote: > I have a huge dataset for which I only want to read in a subset of it. Is it possible to use read.table to read in only a subset of the data? For example, something like read.table('~/data.txt', subset = chromosome=='1' ) > > If not, then why not? This seems to be a feature available in all other statistical software. > > Thanks, > Stacey > > > > __________________________________________________________________ > [[elided Yahoo spam]] > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
