Thanks for the input, but it looks like I found a simple solution.
Turns out that if you assign to lists by name, then R doesn't make extra
copies:
> x<-double(10^9)
> mylist<-list()
> system.time(mylist[[1]]<-x)
user system elapsed
2.992 3.352 6.364
> x<-double(10^9)
> mylist<-list(
On Aug 16, 2013, at 2:23 PM, Gang Peng wrote:
> If you don't want to copy the data, you can use environments. You can first
> define x and y in the global environment and then in the function, use
> function get() to get x, y in the global environment. When you change x and
> y in the function, x
If you don't want to copy the data, you can use environments. You can first
define x and y in the global environment and then in the function, use
function get() to get x, y in the global environment. When you change x and
y in the function, x and y also change in the global environment.
Best,
Gan
Usually R is pretty good about not copying objects when it doesn't need
to. However, the list() function seems to make unnecessary copies. For
example:
> system.time(x<-double(10^9))
user system elapsed
1.772 4.280 7.017
> system.time(y<-double(10^9))
user system elapsed
2.564
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