[R] textConnections so slow!
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Nov 10 20:45:26 CET 2003
On Mon, 10 Nov 2003, Mathieu Drapeau wrote:
> Is it normal that it takes a very long time to generate a connection
> object on a big character vector?
Yes.
> This takes a very long time to process:
> lines <- readLines ("myBigFile.txt")
> data <- scan(textConnection(lines), sep = "\t")
>
> against this that is pretty short to process:
> data <- scan("myBigFile.txt", sep = "\t")
>
> Anyone has any clues how to efficiently do that because I need to use a
> textConnection on a big vector?
Why? There are better ways, even described on the help page!
--
Brian D. Ripley, ripley at stats.ox.ac.uk
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
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