Re: [R] Fast way to determine number of lines in a file

Hi Hadley, Hope this is what you are looking for. This approach provides number of lines in a large 'bzip' file using chunks. testconn <- file("xyzxyz.csv.bz2", open="r") csize <- 1 nolines <- 0 while((readnlines <- length(readLines(testconn,csize))) >0 ) nolines <- nolines+readnlines close(t

Re: [R] Fast way to determine number of lines in a file

had...@rice.edu] Sent: Monday, February 08, 2010 7:16 AM To: R-help Subject: [R] Fast way to determine number of lines in a file Hi all, Is there a fast way to determine the number of lines in a file? I'm looking for something like count.lines analogous to count.fields. Hadley -- http:

Re: [R] Fast way to determine number of lines in a file

> I was looking for a fast line counter as well a while ago and ended up > writing a small function in R: > >  countLines() in the R.utils package > > At least at the time, it was faster than readLines() [for unknown > reasons].  It is also more memory efficient.  It supports connections. >  I don'

Re: [R] Fast way to determine number of lines in a file

I was looking for a fast line counter as well a while ago and ended up writing a small function in R: countLines() in the R.utils package At least at the time, it was faster than readLines() [for unknown reasons]. It is also more memory efficient. It supports connections. I don't think it be

Re: [R] Fast way to determine number of lines in a file

On 02/08/2010 04:16 PM, Hadley Wickham wrote: parser::nlines does it in C. Looks promising, but I need something that uses connections because I'm working with big bzipped files. Hadley Ah... the lack of c-level api for connections again ;-) -- Romain Francois Professional R Enthusiast +3

Re: [R] Fast way to determine number of lines in a file

Hi Ken, > How about something like > length(readLines(fname)) I'm trying to avoid the overhead of reading the file in twice. (I'm trying to preallocate a data structure for a chunked read) Hadley -- http://had.co.nz/ __ R-help@r-project.org mailin

Re: [R] Fast way to determine number of lines in a file

> parser::nlines does it in C. Looks promising, but I need something that uses connections because I'm working with big bzipped files. Hadley -- http://had.co.nz/ __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEAS

Re: [R] Fast way to determine number of lines in a file

If you are willing to use an external program parse the result of: > system("wc -l small.dat") 10 small.dat On Windows there is a wc.exe program in the Rtools distribution. On Mon, Feb 8, 2010 at 9:16 AM, Hadley Wickham wrote: > Hi all, > > Is there a fast way to determine the number of lines i

Re: [R] Fast way to determine number of lines in a file

Hadley Wickham rice.edu> writes: > > Hi all, > > Is there a fast way to determine the number of lines in a file? I'm > looking for something like count.lines analogous to count.fields. > > Hadley How about something like length(readLines(fname)) Ken _

Re: [R] Fast way to determine number of lines in a file

Hi, parser::nlines does it in C. Romain On 02/08/2010 03:16 PM, Hadley Wickham wrote: Hi all, Is there a fast way to determine the number of lines in a file? I'm looking for something like count.lines analogous to count.fields. Hadley -- Romain Francois Professional R Enthusiast +33(0) 6

[R] Fast way to determine number of lines in a file

Hi all, Is there a fast way to determine the number of lines in a file? I'm looking for something like count.lines analogous to count.fields. Hadley -- http://had.co.nz/ __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-he