[R] transfer string to expression

Duncan Murdoch murdoch.duncan at gmail.com
Sun Oct 31 21:58:15 CET 2010


On 31/10/2010 4:47 PM, Wu Gong wrote:
>
> Hi Duncan:
>
> I'm curious about the environment setting. ?eval says:
>
> "If envir is not specified, then the default is parent.frame() (the
> environment where the call to eval was made). "
>
> So what's the difference between set envir=parent.frame() or not?

If you pass parent.frame() as an argument, it will be one level up: 
it's the parent of the function that calls eval.  If you leave it at the 
default, it's the parent of eval, i.e. the function that calls it.

Duncan Murdoch



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