R limits documented?

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).

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