On 09/06/2011 06:24 AM, Mark Ebbert wrote: > Dear R gurus, > > I am trying to write several large matrices (~ 1GB) to separate files. I have > learned that write.table is simply too slow for this task and was attempting > to use write.matrix, but write.matrix does not have the ability to include > row names in the output. Anyone know why that's the case? I've seen a thread > stating that write.matrix is the way to go for large prints to files, but it > doesn't do what I need it to. Since write.matrix wasn't working I tried both > sink and capture.output, but then the output is printed to the file using the > same 'width' restrictions as the general "options(width=)" limit. > > Any ideas on how to print a large matrix with row names? I could write a perl > script to modify the files after the fact, but I shouldn't have to do that. > > Thanks for your help! > > Mark T. W. Ebbert > ______________________________________________ > 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.
Hi, What do you want with the data? If you want to store an R matrix on disk for later use in R, take a look at ?save. If it is for use in another programming language, I would write the matrix in binary format (?writebin). This saves a lot of space and prevents any (significant) rounding errors. It is probably also quite a bit faster. If you really need some more metadata (such as rownames), I would add a second text file which stores this information. Sort of a binary file plus a header, which is a quite common format for storing data. Maybe you can even find a standard binary format which you can use. But it is impossible to comment on this because you did not provide information as to what you want to do with the saved data. good luck! Paul -- Paul Hiemstra, Ph.D. Global Climate Division Royal Netherlands Meteorological Institute (KNMI) Wilhelminalaan 10 | 3732 GK | De Bilt | Kamer B 3.39 P.O. Box 201 | 3730 AE | De Bilt tel: +31 30 2206 494 http://intamap.geo.uu.nl/~paul http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770 ______________________________________________ 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.
