[R-sig-teaching] pros/cons of teaching attach()
maechler at stat.math.ethz.ch
Thu Sep 23 21:50:24 CEST 2010
>>>>> Douglas Bates <bates at stat.wisc.edu>
>>>>> on Wed, 22 Sep 2010 07:10:14 -0500 writes:
> On Wed, Sep 22, 2010 at 4:04 AM, Joshua Wiley
> <jwiley.psych at gmail.com> wrote:
>> Thanks to everyone for your thoughtful replies. I think
>> I am inclined not to use attach, but to bring it up and
>> briefly mention some of the mistakes that are easy to
>> make. If students already know/use attach, it will at
>> least be clear why I do not use it, and for students
>> unfamiliar with it, they should not be tempted to start.
>> Thanks again for all the responses!
> I avoid teaching attach() and discourage its use if the
> students have already seen it. I do teach both with and
> within (with provides read-only access, within provides
> read-write access to the variable names in a data frame or
> a list). As mentioned in an earlier reply in this thread,
> the use of extractor functions, like residuals() or
> fitted() or coef(), should be preferred to reaching inside
> a data object and grabbing a component that may or may not
> continue to be defined in future versions,
> The supplementary material on R that I use in a first-year
> grad course on applied statistics is available, for this
> semester, at www.stat.wisc.edu/~st849-1/Rnotes My approach
> to data organization is shown in the "Introduction to R".
I agree entirely with Doug and Gavin(mostly) and Jonathan.
However, there's one remark about attach() that "everyone" seems to
forget (AFAIR even Doug ;-):
Do consider (and teach!) using attach("foobar.rda") for *.rda files
which I often find quite preferable to load().
I forgot who (from R-core) introduced this idea,
but I do like it: It rehabilitates attach() into a "decent R
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