[R] Slight problem in sort

[Frank E Harrell Jr]

In

platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    1                
minor    7.1              
year     2003             
month    06               
day      16               
language R                

I get

> sort(c(3,1,NA))
[1] 1 3

Shouldn't NAs be retained by default?

Thanks -Frank
---
Frank E Harrell Jr              Prof. of Biostatistics & Statistics
Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences
U. Virginia School of Medicine  http://hesweb1.med.virginia.edu/biostat