R help - Nov 2005 - what's the meaning of these in R-lang?

In this case the environment contains the variables local to the function, and
its enclosure is the environment of the enclosing function.(R-lang:p11)

I want to know if the "enclosing function" means the closure of the
function? for example ,if I call function mean(),and the create an
environment,say e1,then the enclosure of e1 is the namespace of base package?
Right?

Thank you!

ronggui <042045003 at fudan.edu.cn> writes:
> In this case the environment contains the variables local to the
> function, and its enclosure is the environment of the enclosing
> function.(R-lang:p11)
Page number are of dubious value for documents in multiple formats. It
is page 5 in the PDF version on CRAN!
> 
> I want to know if the "enclosing function" means the closure of
the
> function? for example ,if I call function mean(),and the create an
> environment,say e1,then the enclosure of e1 is the namespace of base
> package? Right?
No. A closure of a function is the function plus its environment. 

For "enclosing function", consider

f <- function() {
        print(environment())
        hello <- "Hi, babe!"
        g <- function() print(hello)
        g
}
myfun <- f() 
myfun()
environment(myfun)


The enclosing function of g, and hence of myfun, is f. The evaluation
environment of g has the evaluation environment of f as its enclosure. 

(The text is arguably imprecise: "evaluation environment of the
enclosing function call" would be better, especially since
environment(f) is something different.)

-- 
   O__  ---- Peter Dalgaard             ??ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907

Thanks very much.
>ronggui <042045003 at fudan.edu.cn> writes:
>
>> In this case the environment contains the variables local to the
>> function, and its enclosure is the environment of the enclosing
>> function.(R-lang:p11)
>
>Page number are of dubious value for documents in multiple formats. It
>is page 5 in the PDF version on CRAN!
>
>> 
>> I want to know if the "enclosing function" means the closure
of the
>> function? for example ,if I call function mean(),and the create an
>> environment,say e1,then the enclosure of e1 is the namespace of base
>> package? Right?
>
>No. A closure of a function is the function plus its environment. 
>
>For "enclosing function", consider
>
>f <- function() {
>        print(environment())
>        hello <- "Hi, babe!"
>        g <- function() print(hello)
>        g
>}
>myfun <- f() 
>myfun()
>environment(myfun)
>
>
>The enclosing function of g, and hence of myfun, is f. The evaluation
>environment of g has the evaluation environment of f as its enclosure. 
I think I get your point.

I would like to express what I think using the folloing
code:
> debug(mean)
> mean(1:10)
debugging in: mean(1:10)
debug: UseMethod("mean")
Browse[1]> environment()
<environment: 0236EDA0>  # the evaluation environment.
Browse[1]> parent.env(environment()) 
<environment: namespace:base> # the enclosure of the evaluation
environment.
Browse[1]> 
exiting from: mean(1:10)
[1] 5.5
> environment(mean)
<environment: namespace:base> # the environment of mean.

So what "# the enclosure of the evaluation environment." is always the
same as "# the environment of function (here is mean)" .

Am I wrong again?


Regards!
>(The text is arguably imprecise: "evaluation environment of the
>enclosing function call" would be better, especially since
>environment(f) is something different.)
Yes,It's easier to understand by "evaluation environment of the
enclosing function call" 

>
>-- 
>   O__  ---- Peter Dalgaard             佖ster Farimagsgade 5, Entr.B
>  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
> (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
>~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45)
35327907
= = = = = = = = = = = = = = = = = = = 			


 

2005-11-24

------
Deparment of Sociology
Fudan University

My new mail addres is ronggui.huang at gmail.com
Blog:http://sociology.yculblog.com