Hi!
That is somewhat strange.
§R>2^100
[1] 1.267651e+30
§R> x <- 2^50
§R> y <- x + 1
§R> y-x
[1] 1
§R>x
[1] 1.1259e+15
§R>x+1
[1] 1.1259e+15
len
From: Duncan Murdoch [murd...@stats.uwo.ca]
Sent: Tuesday, January 26, 2010 4:09 PM
To: Blanford, Glenn
Cc: r-help@R-project.org
Subject: Re: [R] large integers in R
On 26/01/2010 3:25 PM, Blanford, Glenn wrote:
> Has there been any update on R's handling large integers greater than 10^9
(between 10^9 and 4x10^9) ?
>
> as.integer() in R 2.9.2 lists this as a restriction but doesnt list the
actual limit or cause, nor if anyone was looking at fixing it.
Integers in R are 4 byte signed integers, so the upper limit is 2^31-1.
That's not likely to change soon.
The double type in R can hold exact integer values up to around 2^52.
So for example calculations like this work fine:
> x <- 2^50
> y <- x + 1
> y-x
[1] 1
Just don't ask R to put those values into a 4 byte integer, they won't fit:
> as.integer(c(x,y))
[1] NA NA
Warning message:
NAs introduced by coercion
Duncan Murdoch
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