[R] Data frames, passing by value, and performance

[Gabor Grothendieck]

If you don't modify the data frame in your function it won't
physically make a new copy.

On Mon, May 24, 2010 at 10:29 AM,  <gschultz at scriptpro.com> wrote:
> I understand that everything passed to an R function is passed "by
> value".  This would seem to include data frames, which my current
> application uses heavily, both for storing program inputs, and holding
> intermediate and final results.  In trying to get greater performance
> out of my R code, I am wondering if there is any clean way to access
> data frames without having them copied all the time.  Or is my only
> option to make them global, and write to them using <<-  ?
>
> I have considered using matrices, but I like the self-documenting aspect
> of data frame column names.  Input/output to disk is not the issue here,
> as that does not take long in my case.  It's just the internal parameter
> passing that I'm concerned about.
>
> (I've checked R-FAQ, R-lang and searched the R-help archives, but didn't
> see any specific mentions of this.)
>
> Thanks.
>
> Grant Schultz
>
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