[R] Passing multiple object names to a user-defined R fn XXXX

[Bert Gunter]

A minor quibble.

I would argue that R best practice would be to keep the summarization
and printing separate; viz

df.set <- function(...){
        dots <- list(...)  # all those objects in a list

}

On Mon, Oct 14, 2013 at 8:43 AM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
> Hello,
>
> You should put all those data frames in a list and then use the list (just
> one object).
> But if you have several objects in your workspace and need to write a
> function that accepts a varying number of arguments, use the dots argument:
>
> df.set <- function(..., by){
>         dots <- list(...)  # all those objects in a list
>         for(d in dots)
>                 print(summary(d))
>         invisible(NULL)
> }
>
> d1 <- data.frame(x = 1:4, y = 5:8)
> d2 <- data.frame(a = 1:10, b = 11:20)
>
> df.set(d1, d2)
>
>
> Note that I don't use c(d1, d2), it will give something completely
> different. c() has unwanted side effects. Try it.
>
>
> Hope this helps,
>
> Rui Barradas
>
> Em 14-10-2013 16:09, Dan Abner escreveu:
>>
>> Hi all,
>>
>> I am attempting to write an R fn that will accept multiple (but varying on
>> how many) objects (usually data frames) as inputs and return summary
>> output.
>>
>> What is the best way to pass the object names to the fn (I have thought of
>> 2 options below) AND how do I then use the names inside the fn to
>> reference
>> the actual object (I assume that I would need something like get(x[1]) for
>> example to have "d1" resolve the the object d1. Correct?
>>
>> The 1st option I thought of was to pass the object names as a character
>> vector in the call to the fn:
>>
>> set.matrix<-df.set(c("d1","d2","d3","d4","d5","d6","d7","d8"),by="ID")
>> 2nd option: Is something like this possible:
>>
>> set.matrix<-df.set(c(d1,d2,d3,d4,d5,d6,d7,d8),by="ID")
>>
>>         [[alternative HTML version deleted]]
>>
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>>
>
> ______________________________________________
> R-help at 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.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

(650) 467-7374