R help - Sep 2003 - Integers in S-Plus and R

I wish to comment on interesting and inconsistent behavior of both 
S-Plus and R with integers.

	  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.

	  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.

Spencer Graves

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