as.numeric with tclvalue redux

Hi again R People:

This works fine:
  

library(tcltk)
a <- tclVar("4.5")
as.numeric(tclvalue(a))
    

[1] 4.5
  

#But if you have:
b <- tclVar("pi")
as.numeric(tclvalue(b))
    

[1] NA
Warning message:
NAs introduced by coercion
  

Is anyone aware of a way around this, please?

  

Brian already told you: Parse and eval.

 > eval(parse(text=as.character(tclvalue(tclVar("pi")))))
[1] 3.141593

(Beware: Depending on the environment in which you eval(), strange 
things can happen if you use the name of an internal variable in your 
function)

What happened with the Inf issue? I can't reproduce that:

 > as.numeric(as.tclObj("Inf"))
[1] Inf

O__  ---- Peter Dalgaard             ?ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907