On Mon, 7 Nov 2005, Stuart Macgregor wrote: > Hi, > I want to use R within a unix shell script where I repeatedly open > and close R (doing some computation within R whilst it is open). i.e. > something like > > #!/bin/sh > R --vanilla << EOF > # some R commands > EOF > # some unix commands > R --vanilla << EOF > # some R commands > EOF > # some unix commands > ...etc > > the problem is that since I open and close R many times, the shell > script takes a long time to run (R takes ~1 second to start up, even on > a fast machine; I've tried various linux installations and versions of R > from 1.7 to 2.2). Is there some way of making R start up faster? I've > tried altering the memory start options but this makes little > difference.
[I don't think your machine _is_ 'fast'! I am seeing 0.3s for a complete R session on an Opteron 250. We have worked hard to reduce the start-up time to those levels over the period you quote: please do not belittle those efforts. R is fast (several times at least) compared to all other software I use of similar complexity.] On my 2-year-old i386 box a complete empty session takes 0.5s. You can reduce that a lot by using fewer default packages. For example, if you don't need methods or graphics or datasets, R_DEFAULT_PACKAGES="utils,stats" reduces that to 0.3s, and R_DEFAULT_PACKAGES=NULL reduces it to 0.05s. We use the latter when using R for scripting (e.g. in R CMD INSTALL). -- 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 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
