On Sat, 12 Feb 2011, Uwe Ligges wrote:
I think it is easiest to point people to the manual "R Internals" for
questions on the size of integers, pointers etc.
But ?"Memory-limits" is a good start.
The messages below (which were not from a current version of R with
that call!) come from
as.integer(50000 * 50000)
[1] NA
Warning message:
NAs introduced by coercion
and times = NA is of course invalid.
Best,
Uwe Ligges
On 12.02.2011 03:24, David Winsemius wrote:
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
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--
Brian D. Ripley, rip...@stats.ox.ac.uk
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
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