[R] Integers in S-Plus and R
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Sep 15 09:25:39 CEST 2003
On Sun, 14 Sep 2003, Spencer Graves wrote:
> I wish to comment on interesting and inconsistent behavior of both
> S-Plus and R with integers.
I think both are consistent: they are just different from each other.
> In R 1.7.1 for Windows, is.integer(2) is FALSE, though
> is.integer(1:2) and is.integer(max(1:2)) are both TRUE. S-Plus 6.1
> produces TRUE for all three cases.
Yes, that's as documented. Note that `2' was not integer in S-PLUS 1.x to
4.x (including 2000), so this is rather an inconsistency in S-PLUS
versions.
> Meanwhile, as.integer(1e111) produces NA in R 1.7.1 and 2147483647 in
> S-Plus 6.1. This behavior is consistent with the documentation in both
> cases: R says, "The answer will be `NA' unless the coercion succeeds."
> S-Plus says, "The numbers are truncated (moved to the closest integer
> ...)."
>
> Just one more thing to consider when trying to produce transportable
> scripts.
Not that in porting code (both ways) I have ever found either to be a
problem.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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