[R] function to avoid <<-

[Karim Mezhoud]

Hi,
An other alternative using "assign" function

func <- function(){
X <- 5
assign("X", X, envir = .GlobalEnv)
}


  Ô__
 c/ /'_;~~~~kmezhoud
(*) \(*)   ⴽⴰⵔⵉⵎ  ⵎⴻⵣⵀⵓⴷ
http://bioinformatics.tn/



On Tue, Dec 2, 2014 at 8:40 PM, Adams, Jean <jvadams at usgs.gov> wrote:

> Glad to see this query and the responses.  You all just helped me to
> eliminate the use of global variables from my R package.  I knew they were
> not recommended, but I didn't know how to get around using them.
>
> Thanks!
>
> Jean
>
> On Tue, Dec 2, 2014 at 10:59 AM, Karim Mezhoud <kmezhoud at gmail.com> wrote:
>
>> OK thanks as:
>>
>> myenv <- new.env(parent = emptyenv())
>> fun <- function(){
>> fun1 <- function(){
>> myenv$X <- 5
>> }
>>
>> }
>> fun()
>> ls(myenv)
>> #X
>> X
>> #5
>>
>>   Ô__
>>  c/ /'_;~~~~kmezhoud
>> (*) \(*)   ⴽⴰⵔⵉⵎ  ⵎⴻⵣⵀⵓⴷ
>> http://bioinformatics.tn/
>>
>>
>>
>> On Tue, Dec 2, 2014 at 5:47 PM, Greg Snow <538280 at gmail.com> wrote:
>>
>> > By "At the top level" Hadley meant to put that code outside of the
>> > function definition.  In you source file that line should be very near
>> the
>> > top, before any function definitions.  Then "myenv" will not be
>> temporary
>> > (well it will go away when you end the R session).  Further, when this
>> code
>> > is compiled into a package then "myenv" becomes package local, meaning
>> that
>> > functions within the package can access it and the objects inside of it,
>> > but it will not interfere with any other packages or the global
>> environment.
>> >
>> > On Tue, Dec 2, 2014 at 9:32 AM, Karim Mezhoud <kmezhoud at gmail.com>
>> wrote:
>> >
>> >> Thanks Dr Hadley,
>> >>
>> >> but when I use a function the myenv remains temporary and I am to face
>> the
>> >> same problem.
>> >>
>> >>
>> >> fun <- function(){
>> >>
>> >> myenv <- new.env(parent = emptyenv())
>> >>
>> >> fun1 <- function(){
>> >> myenv$X <- 5
>> >> }
>> >>
>> >> }
>> >>
>> >> ls(myEnv)
>> >> #character(0)
>> >>
>> >>   Ô__
>> >>  c/ /'_;~~~~kmezhoud
>> >> (*) \(*)   ⴽⴰⵔⵉⵎ  ⵎⴻⵣⵀⵓⴷ
>> >> http://bioinformatics.tn/
>> >>
>> >>
>> >>
>> >> On Tue, Dec 2, 2014 at 4:17 PM, Hadley Wickham <h.wickham at gmail.com>
>> >> wrote:
>> >>
>> >> > At the top level do:
>> >> >
>> >> > myenv <- new.env(parent = emptyenv())
>> >> >
>> >> > Then in your functions do
>> >> >
>> >> > myenv$x <- 50
>> >> > myenv$x
>> >> >
>> >> > etc
>> >> >
>> >> > You also should not be using data() in that way. Perhaps you want
>> >> > R/sysdata.rda. See http://r-pkgs.had.co.nz/data.html for more
>> details.
>> >> >
>> >> > Hadley
>> >> >
>> >> > On Tue, Dec 2, 2014 at 2:28 AM, Karim Mezhoud <kmezhoud at gmail.com>
>> >> wrote:
>> >> > > Dear All,
>> >> > >
>> >> > > I am writing a GUIpackage that needs global variables.
>> >> > > I had many warning message when I checked the code as for example:
>> >> > > geteSet: no visible binding for global variable ‘curselectCases’
>> >> > > I would like to write a function that creates a global place for
>> >> Objects
>> >> > to
>> >> > > be loaded as:
>> >> > >
>> >> > >
>> >> > > Fun <- function(){
>> >> > >
>> >> > > Object <- 5
>> >> > >
>> >> > > Var2Global <- function(Object){
>> >> > > .myDataEnv <- new.env(parent=emptyenv()) # not exported
>> >> > > isLoaded <- function(Object) {
>> >> > >     exists(Object, .myDataEnv)
>> >> > > }
>> >> > > getData <- function(Object) {
>> >> > >     if (!isLoaded(Object)) data(Object, envir=.myDataEnv)
>> >> > >     .myDataEnv[[Object]]
>> >> > > }
>> >> > > }
>> >> > >
>> >> > > }
>> >> > >
>> >> > > To avoid the use of:  Object <<- 5
>> >> > >
>> >> > > but it seems not working yet. Object == 5 is not a global variable
>> >> after
>> >> > > running Fun().
>> >> > >
>> >> > > Any Idea?
>> >> > > Thanks
>> >> > >   Ô__
>> >> > >  c/ /'_;~~~~kmezhoud
>> >> > > (*) \(*)   ⴽⴰⵔⵉⵎ  ⵎⴻⵣⵀⵓⴷ
>> >> > > http://bioinformatics.tn/
>> >> > >
>> >> > >         [[alternative HTML version deleted]]
>> >> > >
>> >> > > ______________________________________________
>> >> > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> >> > > 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.
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > http://had.co.nz/
>> >> >
>> >>
>> >>         [[alternative HTML version deleted]]
>> >>
>> >> ______________________________________________
>> >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> >> 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.
>> >>
>> >
>> >
>> >
>> > --
>> > Gregory (Greg) L. Snow Ph.D.
>> > 538280 at gmail.com
>> >
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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.
>>
>
>

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