Dear John Fox:


I highly appreciate

your help!!!  Problems solved.

     Best Wishes Always.


2013/11/6 John Fox <jfox@mcmaster.ca>

> Dear Zhong-Yuan Zhang,
>
> R is lexically scoped. Pretending that you're using a different programming
> language is probably a bad idea.
>
> The findGlobals() function in the codetools package, which is part of the
> standard R distribution, can help you locate references to global variables
> (and functions) in a function. For example,
>
> > f <- function() g(a)
>
> > findGlobals(f)
> [1] "a" "g"
>
> > ff <- function() {a <- 10; g(a)}
>
> > findGlobals(ff)
> [1] "{"  "<-" "g"
>
> > fff <- function(a) g(a)
>
> > findGlobals(fff)
> [1] "g"
>
> I hope this helps,
>  John
>
> > -----Original Message-----
> > From: r-help-bounces@r-project.org [mailto:r-help-bounces@r-
> > project.org] On Behalf Of Zhong-Yuan Zhang
> > Sent: Wednesday, November 06, 2013 7:32 AM
> > To: r-help@r-project.org
> > Subject: Re: [R] Function does not see variables outside the function
> >
> > Dear Experts:
> >
> >     I am very appreciate your comments and help!
> >
> >     Actually I am a new comer from MATLAB. If the function
> >
> > can see global variables, then it may output wrong results without
> >
> > any error messages. For example, there is a gloabl variable named
> >
> > v, and I write one funciton with one local variable x. However, in some
> > line,
> >
> > I misspelled x to v, which would results in unexpected errors without
> > warning.
> >
> >     In summary, I want to disable the ability to make debugging easier.
> >
> >     Best.
> >
> >
> > 2013/11/5 Carl Witthoft <carl@witthoft.com>
> >
> > > Why would you want to impose this restriction?  Perhaps if you
> > explain what
> > > you are trying to do, we can suggest approaches that will satisfy
> > your
> > > specific needs.
> > > (note- one can always redefine whatever variables are to be
> > "excluded."
> > > E.g.
> > > to keep the body of a function from referring to 'foo' in the calling
> > > environment, just add the line 'foo<-NA' inside the function)
> > >
> > >
> > > Zhong-Yuan Zhang wrote
> > > >      In MATLAB, functions cannot see variables outside the
> > > >
> > > > functions.  However, in R, the functions can do that. Is there
> > > >
> > > > any settings that can disable this ability of functions?
> > > >
> > > >
> > > > ______________________________________________
> > >
> > > > R-help@
> > >
> > > >  mailing list
> > > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > > PLEASE do read the posting guide
> > > > http://www.R-project.org/posting-guide.html
> > > > and provide commented, minimal, self-contained, reproducible code.
> > >
> > >
> > >
> > >
> > >
> > > --
> > > View this message in context:
> > > http://r.789695.n4.nabble.com/Function-does-not-see-variables-
> > outside-the-function-tp4679762p4679768.html
> > > Sent from the R help mailing list archive at Nabble.com.
> > >
> > > ______________________________________________
> > > R-help@r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide
> > > http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> > >
> >
> >
> >
> > --
> > Zhong-Yuan Zhang (PhD.)
> > Associate Professor
> > School of Statistics
> > Central University of Finance and Economics
> > 39 South College Road, Haidian District, Beijing, P.R.China 100081
> > Email: zhyuanzh@gmail.com
> > Homepage: http://en.stat.cufe.edu.cn/zhongyuanzhang/
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> > guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
>


-- 
Zhong-Yuan Zhang (PhD.)
Associate Professor
School of Statistics
Central University of Finance and Economics
39 South College Road, Haidian District, Beijing, P.R.China 100081
Email: zhyuanzh@gmail.com
Homepage: http://en.stat.cufe.edu.cn/zhongyuanzhang/

	[[alternative HTML version deleted]]

