If you want to read only the alternate columns that contain numerics, then you can probably use:
scan('yourfile', what=c(rep(list(NULL), list(0)), 243), flush=TRUE, fill=TRUE, skip=1) On Nov 10, 2007 12:25 AM, affy snp <[EMAIL PROTECTED]> wrote: > Hi Gabor, > > Thanks a lot! > > The header of the big file looks like as follows: > > probe_set > WM_806_Signal_A > WM_806_call > WM_1716_Signal_A > WM_1716_call > .... > > I only need those columns with the header as like _Signal_A > > Can you suggest how to use sqldf? > > Thanks! > > Allen > > > On Nov 9, 2007 11:47 PM, Gabor Grothendieck <[EMAIL PROTECTED]> wrote: > > 1. You might be able to speed it up somewhat by specifying > > colClasses=. > > > > 2. Another possibility is that the devel version of > > the sqldf package provides an interface which simplifies reading a data file > > into sqlite and from there into R. This is particularly useful if you > > don't want to read it all in. See example 6 on the home page: > > http://sqldf.googlecode.com > > > > 3. If it doesn't change and its ok to read it in slowly once then just > > read it in slowly and save() it. Then you can load() > > it on subsequent runs which should be fast. > > > > On Nov 9, 2007 11:39 PM, affy snp <[EMAIL PROTECTED]> wrote: > > > > > Dear list, > > > > > > I need to read in a big table with 487 columns and 238,305 rows (row names > > > and column names are supplied). Is there a code to read in the table in > > > a fast way? I tried the read.table() but it seems that it takes forever :( > > > > > > Thanks a lot! > > > > > > Best, > > > Allen > > > > > > > > ______________________________________________ > > > 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. > -- 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.