struggling with integers (maximum integer size)

Solution 1:

The largest integer R can hold is

.Machine$integer.max
# [1] 2147483647

This has nothing to do with scientific notation and everything to do with how the computer actually stores the numbers. The current version of R stores integers still as 32bit, regardless of the architecture. This might change in the future though.

see also ?as.integer

Currently you can get access to 64 bit integers through the int64 package

> as.integer(.Machine$integer.max)
[1] 2147483647
> # We get problems with this
> as.integer(.Machine$integer.max + 1)
[1] NA
Warning message:
NAs introduced by coercion 
> # But if we use int64
> library(int64)
> as.int64(.Machine$integer.max) + 1L
[1] 2147483648

Solution 2:

Update to Dason's answer (don't have enough reputation to make a comment):

The int64 package has now been deprecated, however there is now a package called bit64. I was able to achieve the same result using it. The syntax changed only slightly from "as.int64" to "as.integer64".

I.e.

library(bit64)
as.integer64(.Machine$integer.max) + 1L

Solution 3:

seems int64 is already deprecated. I use package bit64, method as.integer64() and solve the problem. details are referred to here.

Solution 4:

There are classes that can handle large integers. I use int64, its vignette is here:

http://cran.r-project.org/web/packages/int64/vignettes/int64.pdf

To use this you just place some normal number into that class then you can add or multiply it across the threshold of what the normal 32bit integer max. Good luck.