[R] Function that works within a package and not when copied in global environment. Why?

Marc Girondot marc_grt at yahoo.fr
Thu Feb 2 15:30:57 CET 2017

Dear experts,

In the package nlWaldTest, there is an hidden function : .smartsub

I can use it, for example:

 > getFromNamespace(".smartsub", ns="nlWaldTest")(pat="x", repl="b" ,
x="essai(b[1], b[2], x[1])")
[1] "essai(b[1], b[2], b[1])"

Now I try to create this function in my global environment:
smartsub <- getFromNamespace(".smartsub", ns="nlWaldTest")

It works also:
 > smartsub(pat="x", repl="b" , x="essai(b[1], b[2], x[1])")
[1] "essai(b[1], b[2], b[1])"

But if I create the function manually:
 > smartsub2 <- function (pat, repl, x)
      args <- lapply(as.list(match.call())[-1L], eval, parent.frame())
      names <- if (is.null(names(args)))
      else names(args)
      dovec <- names %in% vectorize.args
      do.call("mapply", c(FUN = FUN, args[dovec], MoreArgs = 
                          SIMPLIFY = SIMPLIFY, USE.NAMES = USE.NAMES))
 > smartsub2(pat="x", repl="b" , x="essai(b[1], b[2], x[1])")
Error in names %in% vectorize.args : objet 'vectorize.args' introuvable

It fails because vectorize.args is unknown

Indeed smartsub2 is different from smartsub.
 > identical(smartsub, smartsub2)

1/ Why are they different? They are just a copy of each other.

2/ Second question, vectorize.args is indeed not defined before to be 
used in the function. Why no error is produced in original function?

Thanks a lot



Marc Girondot, Pr

Laboratoire Ecologie, Systématique et Evolution
Equipe de Conservation des Populations et des Communautés
CNRS, AgroParisTech et Université Paris-Sud 11 , UMR 8079
Bâtiment 362
91405 Orsay Cedex, France

Tel:  33 1 (0)   Fax: 33 1 (0)
e-mail: marc.girondot at u-psud.fr
Web: http://www.ese.u-psud.fr/epc/conservation/Marc.html
Skype: girondot

More information about the R-help mailing list