Is there a way to store a large number precisely in R?

Question

Is there a way to store a large number precicely in R?

double is stored as a binary fraction and its precision varies with the value, and integer has limited range of 4 bytes.

What if I wanted to store a very large number precisely?

Answer 1

You can try the bigz class from the gmppackage:

> library("gmp")
> 2^10000
[1] Inf
> 2^(as.bigz(10000))
[1] "199506.... and a LOT of more numbers!

It basically stores the number as a string and so avoiding the integer/double limits.

Answer 2

It depends on what you mean by large number:

• If you want numbers above the top end of double precision arithmetic, there is the Brobdingnag package

• If you want more precision there are the gmp and related Rmpfr packages.