[R] Symbolic substitution of expressions into expressions

[Peter Dalgaard BSA]

John Maindonald <john.maindonald at anu.edu.au> writes:

> In the following
> 
> titletxt <- substitute(paste(tx, tilde(y) == sqrt(y)),
>   list(tx="Replace y by "))
> 
> I'd like to be able to replace e.g. sqrt(y) by a symbol or
> symbolic expression that has the effect of inserting sqrt(y)
> into the place that it occupies.  This would allow me to put an
> arbitrary expression into that position.  [One can use text() or
> mtext() etc. to place titletxt on a graph.]
> 
> Any clues would be most welcome.

titletxt <- substitute(paste(tx, tilde(y) == my.y),
   list(tx="Replace y by ",my.y=quote(sqrt(y))))


-- 
   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
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._