[R] Entering numbers with decimals
murdoch at stats.uwo.ca
Sat Apr 8 22:00:45 CEST 2006
On 4/8/2006 3:51 PM, Mike Leahy wrote:
> Hello list,
> I'm just getting started with R, and I'm trying to determine how R
> treats large numbers that have decimals. Take the following two examples:
>> x <- c(999999999999999.9)
>  "999999999999999.87000"
>> y <- c(9999999999999999.9)
>  "10000000000000000.00000"
> I realize that I have no idea what I'm doing as far as using R is
> concerned, but maybe someone can tell me what would be the best way to
> input/output numbers such that they don't get rounded off in unexpected
> ways. I've been searching online and looking through various R manuals,
> but I haven't found anything that really clarifies this so far...
R uses standard double precision storage for floating point numbers,
which means approximately 15-16 decimal place accuracy. There isn't
anything you can easily do to improve this in general, though the gmp
package allows some calculations to high precision.
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