Message-ID: <22700.28120.774874.581304@stat.math.ethz.ch>
Date: 2017-02-21T16:42:00Z
From: Martin Maechler
Subject: possible improvement to ?with examples
In-Reply-To: <afff319d-3390-3b6d-8197-b93d31f99643@mcmaster.ca>
>>>>> Ben Bolker <bbolker at gmail.com>
>>>>> on Thu, 16 Feb 2017 15:37:13 -0500 writes:
> A querent on StackOverflow asked about the with() function
> http://stackoverflow.com/questions/42283479/why-when-to-use-with-function#42283479
> and asked about the example in ?with
> library(MASS)
> with(anorexia, {
> anorex.1 <- glm(Postwt ~ Prewt + Treat + offset(Prewt),
> family = gaussian)
> summary(anorex.1)
> })
> which saves little or no typing relative to
> anorex.1 <- glm(Postwt ~ Prewt + Treat + offset(Prewt),
> family = gaussian, data=anorexia)
> (I would argue that the latter is better practice anyway).
> Could we have something more sensible like
> with(mtcars,mpg[cyl==8 & disp>350])
> ? (It could be contrasted directly with
> mtcars$mpg[mtcars$cyl==8 & mtcars$disp>350]
> )
I now have done something like the above, and have added a
\note{ .. } to warn about "over - use" of with().
Also added a link to Thomas Lumley's paper
Thomas Lumley (2003) \emph{Standard nonstandard evaluation rules}.
\url{http://developer.r-project.org/nonstandard-eval.pdf}
> I'm happy to submit a bug report/patch if that seems appropriate.
Thank you, Ben!
Martin