R limits documented?
On Feb 11, 2011, at 8:46 PM, Simon Urbanek wrote:
On Feb 11, 2011, at 8:45 PM, Simon Urbanek wrote:
On Feb 11, 2011, at 7:55 PM, David Winsemius wrote:
On Feb 11, 2011, at 7:09 PM, Dominick Samperi wrote:
Is there documentation on R limits? That is, max matrix size, etc.? Diagnostics when limits are exceeded are not always meaningful. For example:
x <- rep(0,50000*50000)
Error in rep(0, 50000 * 50000) : invalid 'times' argument In addition: Warning message: In as.vector(data) : NAs introduced by coercion
x <- rep(0,40000*50000) gc()
used (Mb) gc trigger (Mb) max used (Mb) Ncells 4673306 249.6 6945861 371.0 5315868 283.9 Vcells 2165579376 16522.1 4374103452 33371.8 4165580443 31780.9
object.size(x)
16000000040 bytes So that is about 2/3 of my installed memory. This seems to be a limitation due to the maximum positive integer being ~ 2*10^9
2*10^9 < 50000*50000
[1] TRUE
2*10^9 < 40000*50000
[1] FALSE
The actual limit is for obvious reasons 2^31-1
as.integer(2^31-1)
[1] 2147483647
as.integer(2^31)
[1] NA
Warning message:
NAs introduced by coercion
(ok, for those that this is not obvious: the integer type ("int" in
C) is 32-bit wide and it is a signed type so the range is
-2^31-1 .. 2^31-1 -- the minus one on each side is the
representation of NA and 0 respectively).
correction: the range should have read -(2^31-1) .. 2^31
I was using the number given in the help page documentation for "integer". (Part of the question was whether it was "documented".) I did understand that it was d/t the 4 byte range. Regarding the second part of the OP's question.... this is from the "character" help page: "as.character truncates components of language objects to 500 characters (was about 70 before 1.3.1)." And there was a posting from Prof Ripley regarding some other limitations that had been recently modified: https://stat.ethz.ch/pipermail/r-devel/2010-November/058989.html
David. > >> Cheers, >> Simon >> >>>> >>>> Here's another example: >>>>> library(orthopolynom) >>>>> hermite <- hermite.h.polynomials(1001) >>>>> hermite[[1001]] # should display 1000-th degree polynomial >>>> Error in if (signs[1] == "- ") "-" else "" : >>>> missing value where TRUE/FALSE needed >>> >>> Sounds as though the maximum length of an element of type >>> character has been exceeded. >>>> >>>> Thanks, >>>> Dominick > David Winsemius, MD West Hartford, CT