On Thu, 4 Sep 2008, Dmitriy Skvortsov wrote:
Hi all,I have large compressed text tab delimited files,
I am trying to write efficient function to read them,
I am using gzfile() and readLines()
zz <- gzfile("exampl.txt.gz", "r") # compressed file
system.time(temp1<-readLines(zz ))
close(zz)
which work fast, and create vector of strings.
The problem is to parse the result, if I use strsplit it takes longer then
decompress file manually , read it with scan and erase it.
Can anybody recommend an efficient way of parsing large vector ~200,000
entries
'parse'? What is wrong with using read.delim (reading 'tab delimited
files' is its job)? It (and scan) work with gzfile connections, so there
is no need to decompress manually.
See the 'R Data Import/Export Manual' for how to use read.delim efficiently.
Dmitriy
[[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.
PLEASE do.
--
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
______________________________________________
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.
