Since there are many rows, using read.table we spent too much on reading in rows that we do not want. We are wondering if there is a way to read only rows that we are interested in. Thanks,
-james > I think you can use readLines(n=1) in loop to skip unwanted rows. > > On Mon, Jun 1, 2009 at 12:56 AM, <g...@ucalgary.ca> wrote: >> Thanks, Juliet. >> It works for filtering columns. >> I am also wondering if there is a way to filter rows. >> Thanks again. >> -james >> >>> One can use colClasses to set which columns get read in. For the >>> columns you don't >>> want you can set those to NULL. For example, >>> >>> cc <- c("NULL",rep("numeric",9)) >>> >>> myData <- >>> read.table("myFile.txt",header=TRUE,colClasses=cc,nrow=numRows). >>> >>> >>> On Wed, May 27, 2009 at 12:27 PM, Â <g...@ucalgary.ca> wrote: >>>> We are reading big tables, such as, >>>> >>>> Chemicals <- >>>> read.table('ftp://ftp.bls.gov/pub/time.series/wp/wp.data.7.Chemicals',header >>>> = TRUE, sep = '\t', as.is =T) >>>> >>>> I was wondering if it is possible to set a filter during loading so >>>> that >>>> we just load what we want not the whole table each time. Thanks, >>>> >>>> -james >>>> >>>> ______________________________________________ >>>> 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. >> > > > ______________________________________________ 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.