R help - Sep 2013 - How to avoid searching variables in global environment

For example:

a <- 1

f <- function(b){
    return(a+b)
}


when we call function f(2), r will search the local environment first, if
it cannot find a, it will search global environment, and return 3. How to
avoid r searching the global environment and return an error when we call
this function?

Thanks.

	[[alternative HTML version deleted]]

Hi,

You need to specify that a is an argument to the function:

On Thu, Sep 12, 2013 at 3:56 PM, Gang Peng <michael.gang.peng at
gmail.com> wrote:
> For example:
>
> a <- 1
>
> f <- function(b){
>     return(a+b)
> }
>
f <- function(b, a) {
    return(a+b)
}
> when we call function f(2), r will search the local environment first, if
> it cannot find a, it will search global environment, and return 3. How to
> avoid r searching the global environment and return an error when we call
> this function?
The function will now give an error if a is not specified.

Sarah

-- 
Sarah Goslee
http://www.functionaldiversity.org