Re: [Rd] html help fails for named vector objects (PR#9927)

From: P Ehlers <ehlers_at_math.ucalgary.ca>
Date: Sun, 23 Sep 2007 03:52:35 -0600

There seems also to be a difference between the way 'help()' and '?' handle 'topic' in some cases.

Consider:
lm <- "aov"

The following all bring up help for 'lm': ?lm
?"lm"
help("lm")

This opens help for 'aov':
help(lm)

It seems that "?" doesn't care about quoting, but "help" does. Did I miss something in the docs?
(If it matters, I'm using options(chmhelp=TRUE).)

 > sessionInfo()
R version 2.6.0 beta (2007-09-18 r42895) i386-pc-mingw32

locale:
LC_COLLATE=English_Canada.1252; [snip]

attached base packages:
[1] stats graphics grDevices utils datasets methods base

Prof Brian Ripley wrote:
> On a normal R help system any version of help(letters) tries to give you
> help on a, b, etc. This is intentional (although the documentation is
> unclearly worded), and has been the case since at least R 2.0.0.
> Some versions of help will display only the first topic.
>
> If help(letters, htmlhelp=FALSE) does something else on your system, that
> is a MacOS-specific bug since the topic selected should not depend on the
> optional arguments.
>
> What is unclear from the documentation is what should happen with
>
> help(c("help", "help.search"))
>
> It seems that for text help you get the first, for htmlhelp both.
>
> There are two things we could do to help (apart from clarifying the
> documentation):
>
> 1) If 'topic' is neither a name nor a character vector (e.g. an expression
> like the last example) give an explicit error.
>
> 2) if topic is a character vector of length > 1, use the name.
>
>
> On Sun, 23 Sep 2007, John.Maindonald_at_anu.edu.au wrote:
>

>>   help(letters, htmlhelp=TRUE) fails.
>>
>> Under the Mac OSX gui, the message is 'Help for the topic "a" was not
>> found.' Under the version documented below, and under Windows, the
>> message is
>>
>>   "No documentation for 'a' in specified packages and libraries:"
>> repeated for all the elements of letters, then followed by
>>   "you could try 'help.search("a")'",
>> again repeated for all elements of letters.
>>
>> The outcome seems similar for any character vector (including matrix)
>> object, e.g. the matrix 'primateDNA' in the DAAGbio package.
>>
>> The following have the expected result
>>   help("letters", htmlhelp=TRUE)
>>   help(letters, htmlhelp=FALSE)

>
> But the documented and actual results are the same, and different in the
> two cases.
>
>> The same result is obtained with R-2.5.1.
>>
>>
>> --please do not edit the information below--
>>
>> Version:
>> platform = i386-apple-darwin8.10.1
>> arch = i386
>> os = darwin8.10.1
>> system = i386, darwin8.10.1
>> status = beta
>> major = 2
>> minor = 6.0
>> year = 2007
>> month = 09
>> day = 22
>> svn rev = 42941
>> language = R
>> version.string = R version 2.6.0 beta (2007-09-22 r42941)
>>
>> Locale:
>> C
>>
>> Search Path:
>> .GlobalEnv, package:testpkg, package:stats, package:graphics,
>> package:grDevices, package:utils, package:datasets, package:methods,
>> Autoloads, package:base
>>
>> John Maindonald             email: john.maindonald_at_anu.edu.au
>> phone : +61 2 (6125)3473    fax  : +61 2(6125)5549
>> Centre for Mathematics & Its Applications, Room 1194,
>> John Dedman Mathematical Sciences Building (Building 27)
>> Australian National University, Canberra ACT 0200.
>>
>> ______________________________________________
>> R-devel_at_r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>

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https://stat.ethz.ch/mailman/listinfo/r-devel Received on Sun 23 Sep 2007 - 09:56:10 GMT

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