[R] = or <-

[Sébastien]

Thanks Erik and Gabor for this precision,

I guess that my misunderstanding of these concepts came from some bad 
habits I took during my self-learning experience of R (especially, 
copy/paste of old codes where <- was used for function arguments and did 
not produce error messages).

Sebastien

Erik Iverson a écrit :
>
>
> Sébastien wrote:
>> Dear R-users,
>>
>> I have written a short VB application to clean and format my R code. 
>> Everything works fine except one small issue that I did not expected; 
>> it is related the automatic replacement of assignment signs from "=" 
>> to "<-". Most functions or arguments seem to accept either = or <-, 
>> but some don't (e.g.  ls(all=TRUE)). The result is that my supposedly 
>> clean codes do not run anymore :-(
>> Is there a way to know the list of arguments/functions that do not 
>> accept "<-" signs ?
>
> You are surely mixing two concepts here.
>
> When you are doing an assignment of a value to a variable, you may use 
> either <- or =.  Example
>
> a <- 2
> a = 2
>
> both bind the value of 2 to the symbol "a".
>
> When you call a function, for example ls, you can specify the argument 
> names, such as ls(all = TRUE).
>
> If you attempted ls(all <- TRUE), the value of TRUE will be assigned 
> to the symbol 'all', and then ls will be evaluated with its first 
> argument "names" as TRUE, which produces your error.  You almost 
> certainly want ls(all = TRUE).  After the error, try typing 'all' at 
> the R prompt.  The 'all' function definition has now been overwritten 
> and is simply TRUE, which you probably do not want either.
>
> So, there really is no concept of whether or not a function "accepts 
> <- signs".  You want to use = in your function calls, since the '<-' 
> method is actually assigning values.
>
> Hope that helps,
> Erik
>
>
>>
>> Thanks in advance.
>>
>> Sebastien
>>
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>
>