On May 29, 2014, at 1:13 PM, dansawyer 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, ...)
Not valid R code.
>
> 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.
Learn to use "[[" instead of "$". (There is a warning about not doing what you
are doing in the help page for ?"$" .)
And furthermore when you see this message (which Nabble rather impolitely
removes)
"and provide commented, minimal, self-contained, reproducible code." ... it
means real R code and not pseudo-code as you are currently offering.
David Winsemius
Alameda, CA, USA
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and provide commented, minimal, self-contained, reproducible code.
