[R] referencing a data frame with a pointer, link, alias, etc

Jeff Newmiller jdnewmil at dcn.davis.CA.us
Thu May 29 23:10:02 CEST 2014


Yes and no. There are "lists" that can hold anything, but for normal objects there are no "pass by reference" semantics. The exception to that is environments, but that is really a limited scope of usability. That is, you can receive a changed object in the calling scope and choose to overwrite your original variable if you choose.

If you provided the "minimal reproducible example" asked for you might get some code examples in return.
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Sent from my phone. Please excuse my brevity.

On May 29, 2014 1:13:10 PM PDT, dansawyer <dansawyer at earthlink.net> wrote:
>Good afternoon. 
>
>The question is: does R support pointer like structures? The specific
>problem is:
>
>a function supporting operations on a set of data frames with similar
>structures. 
>
>I have a set of data frames with similar structures. I wish to perform
>similar operations on those data frames. I have successfully created
>and
>tested the operations and am ready to write a local function to perform
>them. To clarify the question below is a pigeon example for the
>question: 
>
>df1 <- (col1, col2, ...)
>df2 <- (col1, col2, ...)
>
>function f(var)
>{var$col1 <- ...
>var$col2 <- ...
>}
>
>f(df1)
>
>Each of the data frames have common column names
>
>I would like for f to be able to perform operations on the data frames
>from
>within the function. I have tried testing variables without success. R
>allows for creating the necessary 'strings' with the correct names,
>however
>I am unable to bind, transform those strings to reference the data
>frames. 
>
>
>
>--
>View this message in context:
>http://r.789695.n4.nabble.com/referencing-a-data-frame-with-a-pointer-link-alias-etc-tp4691436.html
>Sent from the R help mailing list archive at Nabble.com.
>
>______________________________________________
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>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.



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