On Jun 12, 2012, at 12:47 , Oliver Ruebenacker wrote: > Hello Hui, > > On Tue, Jun 12, 2012 at 2:12 AM, Hui Wang <huiwang.biost...@gmail.com> wrote: >> Dear all, >> >> I've run into a question of handling large matrices in R. I'd like to >> define a 70000*70000 matrix in R on Platform: >> x86_64-apple-darwin9.8.0/x86_64 (64-bit), but it seems to run out of memory >> to handle this. Is it due to R memory limiting size or RAM of my laptop? If >> I use a cluster with larger RAM, will that be able to handle this large >> matrix in R? Thanks much! > > Do you really mean 7e4 by 7e4? That would be 4.9e9 entries. If each > entry takes 8 bytes (as it typically would on a 64 bit system), you > would need close to 40 Gigabyte storage for this matrix. I'm not sure > there is a laptop on the market with that amount of RAM.
What's more: log2(4.9e9) = 32.19, i.e. it exceeds the amount of memory that can be addressed with 32-bit pointers (and matrices are vectors internally). This maxes out at 2^31-1 = 2147483647 (maximum of a signed 32-bit integer). In current R-devel, you _can_ actually store larger vectors, but you can't do much with them (yet): > d <- double(49e8) > sum(d) Error: long vectors not supported yet: ../../../R/src/include/Rinlinedfuns.h:100 -- Peter Dalgaard, Professor Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
