[R] Trying to learn how to write a function... can't define a variable??

[Bert Gunter]

WHEW! Have you read An Introduction to R? If not, stop and do so. If
you have, stop and do so again. Or look for other web tutorials (you
may get some suggestions here) or books (CRAN is a good place to look
for this).

The problem is that you are so far from understanding how a function
works, that I wouldn't know where to begin. Ergo the tutorial
suggestions.

May I also suggest that should anyone else care to have a go at
helping, that they reply privately, as this somehow does not seem the
right venue for such basic tutorials.

Cheers,
Bert

On Fri, Sep 7, 2012 at 11:00 AM, wwreith <reith_william at bah.com> wrote:
> I am just starting to experiment with writing a function and have run into
> what seems like a limitation or more likely a lack of understanding on my
> part.
>
> Very Simple Example:  I want to define a function that does 1+1=2.
>
> z<-1
> ADD<-function(x)
> {
> x<-x+1
> }
> ADD(z)
> z
>  output for z is 1 not the expected 2.
>
> Now if I were to do print(x+1) instead of x<-x+1 it does return 2, so the
> function seems ok with x+1, but not ok with x<-. Is there a way to define a
> variable inside a function or am I violating some rule that I don't know
> about?
>
> Thanks for the help!
>
> Will
>
>
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Trying-to-learn-how-to-write-a-function-can-t-define-a-variable-tp4642528.html
> Sent from the R help mailing list archive at Nabble.com.
>
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> and provide commented, minimal, self-contained, reproducible code.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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