[R] Create variable by name

[David Winsemius]

On Oct 6, 2010, at 12:32 PM, Ralf B wrote:

> Can one create a variable through a function by name

Isn't that what "<-" does?

>
> createVariable <- function(name) {
> 	outputVariable = name
> 	name <- NULL
> }
>
> after calling
>
> createVariable("myVar")

?assign   # and isn't this covered in R-FAQ?
?"<-"

 > "myVar" <- NULL
 > myVar
NULL

Doing it a bit differently"

 > "<-"("n1", NULL)
 > n1
NULL

One could always wrap it in a function call.

 > CVN <- function(name) { name <- NULL }
 > CVN("test")
 > test
NULL

If you needed a function that by default created the variable in the  
global environment, then this would work:

 > createGVarNULL <- function(name) {
+ 	assign(name, NULL, envir = .GlobalEnv) }
 > createGVarNULL("test")
 > test
NULL

An "assign" version of "<<-" I suppose.

"myVar" <- NULL
 > myVar
NULL


>
> I would like to have a variable myVar initialized with NULL in my
> environment. Is this possible?
>
> Ralf
>
-- 

David Winsemius, MD
West Hartford, CT