On Thu, Nov 1, 2012 at 2:04 PM, Hafen, Ryan P <ryan.ha...@pnnl.gov> wrote:
> I need to find all global variables being used in a function and 
> findGlobals() in the codetools package works quite nicely.  However, I am not 
> able to find variables that are used in formulae.  Simply avoiding formulae 
> in functions is not an option because I do not have control over what 
> functions this will be applied to.
>
> Here is an example to illustrate:
>
> library(codetools)
>
> xGlobal <- rnorm(10)
> yGlobal <- rnorm(10)
>
> plotFn1 <- function() {
>    plot(yGlobal ~ xGlobal)
> }
>
> plotFn2 <- function() {
>    y <- yGlobal
>    x <- xGlobal
>    plot(y ~ x)
> }
>
> plotFn3 <- function() {
>    plot(xGlobal, yGlobal)
> }
>
> findGlobals(plotFn1, merge=FALSE)$variables
> # character(0)
> findGlobals(plotFn2, merge=FALSE)$variables
> # [1] "xGlobal" "yGlobal"
> findGlobals(plotFn3, merge=FALSE)$variables
> # [1] "xGlobal" "yGlobal"
>
> I would like to find that plotFn1 also uses globals xGlobal and yGlobal.  Any 
> suggestions on how I might do this?

If this is only being applied to your own functions then we can have a
convention when writing them to help it in which we "declare" such
variables so that findGlobals can locate them:


plotFn1 <- function() {
   xGlobal; yGlobal
   plot(yGlobal ~ xGlobal)
}

findGlobals(plotFn1)

-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to