[R] reading a text file, one line at a time

David Winsemius dwinsemius at comcast.net
Sun Aug 15 18:46:26 CEST 2010


On Aug 15, 2010, at 10:58 AM, Data Analytics Corp. wrote:

> Hi,
>
> I have an upcoming project that will involve a large text file.  I  
> want to
>
>  1. read the file into R one line at a time

?readLines

>  2. do some string manipulations on the line
>  3. write the line to another text file.
>
> I can handle the last two parts.  Scan and read.table seem to read  
> the whole file in at once.  Since this is a very large file (several  
> hundred thousand lines), this is not practical.  Hence the idea of  
> reading one line at at time.  The question is, can R read one line  
> at a time?  If so, how?  Any suggestions are appreciated.
>
> Thanks,
>
> Walt
>
> ________________________
>
> Walter R. Paczkowski, Ph.D.
> Data Analytics Corp.
> 44 Hamilton Lane
> Plainsboro, NJ 08536
> ________________________
> (V) 609-936-8999
> (F) 609-936-3733
> walt at dataanalyticscorp.com
> www.dataanalyticscorp.com
>
> _____________________________________________________
>
>
> -- 
> ________________________
>
> Walter R. Paczkowski, Ph.D.
> Data Analytics Corp.
> 44 Hamilton Lane
> Plainsboro, NJ 08536
> ________________________
> (V) 609-936-8999
> (F) 609-936-3733
> walt at dataanalyticscorp.com
> www.dataanalyticscorp.com
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT



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