R help - Mar 2003 - A quirk in `transform'?

A quirk in `transform''? 
> df <- data.frame(x=1:3, y=4:6, z=7:9); df
  x y z
1 1 4 7
2 2 5 8
3 3 6 9
> transform(df,z=z)
  x y z
1 1 4 7
2 2 5 8
3 3 6 9
> transform(df,y=y)
  x y z
1 1 4 7
2 2 5 8
3 3 6 9
> transform(df,x=x)
Error in transform(df, x = x) : Object "x" not
found
> 
_              
platform i386-pc-mingw32
arch     i386           
os       mingw32        
system   i386, mingw32  
status                  
major    1              
minor    6.2            
year     2003           
month    01             
day      10             
language R              

-
Best, 
Steve Wisdom, CT, USA

Steve Wisdom <swisdom at techemail.com> writes:
> A quirk in `transform'? 
..
> > transform(df,x=x)
> Error in transform(df, x = x) : Object "x" not found
Yes (or in argument matching). "x" names the object and thus cannot be
used again as a tag. 

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907