Dear Prof. Ripley, Thanks a lot. I've just looked at Rcompression and it seems to do exactly what I need, though it requires having zlib and bzip2 installed (and I am not sure if this will deter some windows users). I'll also check connections.c, which might be a way to go, or else wait for the release of that version of our package until R 2.7.0 is out.
Best, R. On Thu, Feb 28, 2008 at 8:53 PM, Prof Brian Ripley <[EMAIL PROTECTED]> wrote: > One solution is likely to be the Omegahat package Rcompression. > > Otherwise, R does have internal facilities to do internal (gzip) > compression and decompression (e.g. see the end of > src/main/connections.c), and you could make creative use of serialization > to do the compression. > > > On Thu, 28 Feb 2008, Ramon Diaz-Uriarte wrote: > > > Dear All, > > > > I'd like to be able to have R store (in a list component) a compressed > > data set, and then write it out uncompressed. gzcon and gzfile work in > > exactly the opposite direction. What would be a good way to handle > > this? > > > > Details: > > ---------- > > > > We have a package that uses C; part of the C output is a large sparse > > matrix. This is never manipulated directly by R, but always by the C > > code. However, we need to store that data somewhere (inside an R > > object) for further calls to the functions in our package. We'd like > > to store that matrix as part of the R object (say, as an element of a > > list). Ideally, it would be stored in as compressed a way as possible. > > Then, when we need to use that information, it would be decompressed > > and passed to the C function. > > > > I guess one way to do it is to have C deal with the compression and > > uncompression (e.g., using zlib or the bzip2 libraries) and then use > > readBin, etc, from R. But, if I can, I'd like to avoid our C code > > having to call zlib, etc, so as to make our package easily portable. > > As from R 2.7.0 you will be able to make use of zlib on effectively all > platforms, since it has a public interface on Windows. > > > > > > > Thanks, > > > > R. > > > > -- > > Ramon Diaz-Uriarte > > Statistical Computing Team > > Structural Biology and Biocomputing Programme > > Spanish National Cancer Centre (CNIO) > > http://ligarto.org/rdiaz > > -- > 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 > -- Ramon Diaz-Uriarte Statistical Computing Team Structural Biology and Biocomputing Programme Spanish National Cancer Centre (CNIO) http://ligarto.org/rdiaz ______________________________________________ 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.
