[R] how modify object in parent.env

Gabor Grothendieck ggrothendieck at myway.com
Wed Mar 9 01:06:15 CET 2005


You can use "<<-" like this:

x <- 1:3
local(x[1] <<- x[1]+1)

Vadim Ogranovich <vograno <at> evafunds.com> writes:

: 
: Assign() re-binds the value, not modifies it (the latter is what I
: needed) 
: 
: > -----Original Message-----
: > From: McGehee, Robert [mailto:Robert.McGehee <at> geodecapital.com] 
: > Sent: Tuesday, March 08, 2005 3:48 PM
: > To: Vadim Ogranovich; r-help <at> stat.math.ethz.ch
: > Subject: RE: [R] how modify object in parent.env
: > 
: > This isn't an environment problem. Assigning something to a 
: > get call doesn't make any sense. Use assign.
: > 
: > > a <- 5
: > > get("a") <- 10
: > Error: couldn't find function "get<-"
: > 
: > And from the ?assign help page, you can pick what environment 
: > you want to make the assignment. Just pick the parent environment.
: > 
: > 
: > -----Original Message-----
: > From: Vadim Ogranovich [mailto:vograno <at> evafunds.com]
: > Sent: Tuesday, March 08, 2005 6:36 PM
: > To: r-help <at> stat.math.ethz.ch
: > Subject: [R] how modify object in parent.env
: > 
: > 
: > Hi,
: >  
: > Is it possible to modify an object in the parent.env (as opposed to
: > re-bind)? Here is what I tried:
: >  
: > > x = 1:3
: > # try to modify the first element of x from within a new environment
: > > local(get("x", parent.env(environment()))[1] <- NA)
: > Error in eval(expr, envir, enclos) : Target of assignment expands to
: > non-language object
: > 
: > # On the other hand retrieval works just fine
: > > local(get("x", parent.env(environment()))[1])
: > [1] 1
: > 
: > Thanks,
: > Vadim
: > 
: > ______________________________________________
: > R-help <at> stat.math.ethz.ch mailing list
: > https://stat.ethz.ch/mailman/listinfo/r-help
: > PLEASE do read the posting guide!
: > http://www.R-project.org/posting-guide.html
: >
: 
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