From S@Elli@on @ending from LGCGroup@com  Fri Dec 14 14:50:58 2018
From: S@Elli@on @ending from LGCGroup@com (S Ellison)
Date: Fri, 14 Dec 2018 13:50:58 +0000
Subject: [Rd] Documentation examples for lm and glm
In-Reply-To: <3aee4716-f0d2-c683-0ad8-90ae6c5894ef@gmail.com>
References: <b0027661-4c72-864d-7dea-a78ade7bf808@auckland.ac.nz>
 <3aee4716-f0d2-c683-0ad8-90ae6c5894ef@gmail.com>
Message-ID: <b578698e1aac4d26b75c3f2dc0f560cc@GBDCVPEXC04.corp.lgc-group.com>

FWIW, before all the examples are changed to data frame variants, I think there's fairly good reason to have at least _one_ example that does _not_ place variables in a data frame. 

The data argument in lm() is optional. And there is more than one way to manage data in a project. I personally don't much like lots of stray variables lurking about, but if those are the only variables out there and we can be sure they aren't affected by other code, it's hardly essential to create a data frame to hold something you already have. 
Also, attach() is still part of R, for those folk who have a data frame but want to reference the contents across a wider range of functions without using with() a lot. lm() can reasonably omit the data argument there, too.

So while there are good reasons to use data frames, there are also good reasons to provide examples that don't.

Steve Ellison


> -----Original Message-----
> From: R-devel [mailto:r-devel-bounces at r-project.org] On Behalf Of Ben
> Bolker
> Sent: 13 December 2018 20:36
> To: r-devel at r-project.org
> Subject: Re: [Rd] Documentation examples for lm and glm
> 
> 
>   Agree.  Or just create the data frame with those variables in it
> directly ...
> 
> On 2018-12-13 3:26 p.m., Thomas Yee wrote:
> > Hello,
> >
> > something that has been on my mind for a decade or two has
> > been the examples for lm() and glm(). They encourage poor style
> > because of mismanagement of data frames. Also, having the
> > variables in a data frame means that predict()
> > is more likely to work properly.
> >
> > For lm(), the variables should be put into a data frame.
> > As 2 vectors are assigned first in the general workspace they
> > should be deleted afterwards.
> >
> > For the glm(), the data frame d.AD is constructed but not used. Also,
> > its 3 components were assigned first in the general workspace, so they
> > float around dangerously afterwards like in the lm() example.
> >
> > Rather than attached improved .Rd files here, they are put at
> > www.stat.auckland.ac.nz/~yee/Rdfiles
> > You are welcome to use them!
> >
> > Best,
> >
> > Thomas
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel


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[Rd] Documentation examples for lm and glm
S Ellison