[Rd] sapply(Date, is.numeric)

[McGehee, Robert]

FYI, 
I've tried posting the below message twice to the bug tracking system,
once by email (below), and the second time 5 days later directly to the
bugs.r-project.org website. As far as I can tell, the bug tracking
system hasn't picked this up. Also it looks like the latest "incoming"
bug is dated 25 May 2008, so perhaps others are having difficulty as
well. (cc: r-bugs)

Cheers, Robert


-----Original Message-----
From: McGehee, Robert 
Sent: Monday, July 14, 2008 9:51 AM
To: R-bugs at biostat.ku.dk
Subject: sapply(Date, is.numeric)

R-developers,
The results below are inconsistent. From the documentation for
is.numeric, I expect FALSE in both cases.

> x <- data.frame(dt=Sys.Date())
> is.numeric(x$dt)
[1] FALSE
> sapply(x, is.numeric)
  dt
TRUE

## Yet, sapply seems aware of the Date class
> sapply(x, class)
  dt
"Date"

platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          7.0                         
year           2008                        
month          04                          
day            22                          
svn rev        45424                       
language       R                           
version.string R version 2.7.0 (2008-04-22)

Thanks,

Robert McGehee, CFA
Geode Capital Management, LLC
One Post Office Square, 28th Floor | Boston, MA | 02109
Tel: 617/392-8396    Fax:617/476-6389
mailto:robert.mcgehee at geodecapital.com



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