[R] Problem with long number (from character to numeric class)

[Petr Savicky]

On Wed, Feb 09, 2011 at 07:39:55AM -0800, PtitBleu wrote:
> 
> Thanks for all your answers. I didn't know this limit.
> 
> I finally found another way to go around this problem: luckily the 4 first
> figures are always the same for all these numbers.
> I created a new column with as.numeric(substr(df$BigNumber,5,18)).
> Numbers are now 14-figures long and it is now ok.

14 digits are OK.

The exact limit is 2^53 as may be seen from the following

  diff(2^53 - 5:0)

  [1] 1 1 1 1 1

  diff(2^53 + 0:5)

  [1] 0 2 2 0 0

Since 2^53 > 8999999999999999, even 16 digit integers may be
used, if the first digit is at most 8.

Petr Savicky.