From murdoch at stats.uwo.ca  Wed Jun  8 13:45:39 2005
From: murdoch at stats.uwo.ca (Duncan Murdoch)
Date: Wed Jun  8 13:45:43 2005
Subject: [Rd] Suggestion: help(<package name>)
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Message-ID: <42A6DA63.7020301@stats.uwo.ca>

Torsten Hothorn wrote:
> On Tue, 7 Jun 2005, Duncan Murdoch wrote:
> 
> [...]
> 
> 
>>My proposal (modified following the suggestions I've heard so far) is as
>>follows:
>>
>>  - to check that a couple of help topic aliases exist (<pkg>.package
>>and <pkg>)
>>  - to recommend that <pkg>.package contain general information about
>>the package, and that <pkg> be an alias for it, if it isn't used for
>>some other purpose.
>>  - to write promptPackage() to help create an initial version of
>><pkg>.package.Rd.  It can get some information from the DESCRIPTION
>>file; perhaps it could go looking for a vignette, or the INDEX, or
>>  - to modify the other help system tools to make use of this (e.g. the
>>package:<pkg> heading on a page would become a link to the <pkg>.package
>>alias, etc.)
>>
> 
> 
> as a package author who already provides help pages for general package
> descriptions (`?multcomp' and `?coin' work and, if I remember correctly,
> Martin suggested to include the advertisement this way) I must
> admit that I never say `?foo' when I'm interested in a global overview
> about a new package `foo'.

I do occasionally, but usually it's a waste of time.  This proposal is 
intended to address that.

> Instead, `library(help = foo)' gives what I want to see, namely the title
> and description of a package and all documented topics. One may argue that
> asking `library' for help is not the most obvious thing to do. But people
> able to recall that fitting an ANOVA model requires `aov' and comparing
> two models needs `anova' should be able to have `library' in mind for
> general package information.

As I pointed out, this is okay for people who know R already, but not so 
good for beginners.  The answer to the question "how do I get help on 
foo?" is too complex.

> So, for me having infrastructure for _automatically_ generated overviews
> is very nice, but _forcing_ package authors to provide additional
> meta-information would be less welcome.

What do you think of Henrik's suggestion to generate a help topic giving 
information equivalent to library(help=<pkg>)?  I think this would 
happen at install time (not build time as he said; no need to put this 
in the source tarballs).  If the <pkg>.package alias wasn't defined, the 
installer would automatically create one.

If we had this in place, I'd strengthen the advice in R-Exts not to 
bother with a manually created INDEX file:  that information should go 
into a manually created <pkg>.package topic instead.

Duncan Murdoch


[Rd] Suggestion: help(<package name>)
Duncan Murdoch