[R] how to use "..."

[David Winsemius]

On Jan 20, 2013, at 3:52 PM, Duncan Murdoch wrote:

> On 13-01-20 6:23 PM, David Winsemius wrote:
>>
>> On Jan 20, 2013, at 11:46 AM, Duncan Murdoch wrote:
>>
>>> On 13-01-20 2:28 PM, Steve Taylor wrote:
>>>>> From: Duncan Murdoch
>>>>> Maybe we just need a manual on how to use the existing help
>>>>> system.  But
>>>>> I suspect people who won't read the existing manuals won't read  
>>>>> that
>>>>> one, either.
>>>>
>>>> Duncan, I assume you're being facetious.  Every R user soon learns
>>>> to use help() and help.search() or their equivalents.  We don't
>>>> need a manual to teach that.
>>>
>>> There are other parts of the help system that you don't appear to
>>> know about.  Run help.start() for the main index page.  help() is
>>> kind of a shortcut to the section labelled "Packages".
>>> help.search() gets you to "Search Engine & Keywords".  There are 15
>>> other headings to explore as well.
>>
>>
>> help.search("...")
>>
>> On my Mac after a very long wait it appears I get all of the  
>> functions
>> in every installed package that have a three-dots argument in their
>> argument list displayed in the Usage sections. That does not seem  
>> very
>> "help"-ful. I tried limiting with keyword="programming", that did not
>> appear effective. I wasn't able to figure out from the
>> help(help.search) page what I need to do to constrict to non-Usage
>> matches yet expand to items linked from the help.start() page.
>
> I don't think you're reading the same "help.search" help page that  
> I'm reading.  help.search("...") is pretty clearly documented to do  
> a search for help pages with "alias", "concept" or "title" matching  
> the regular expression "...", i.e. they have three characters in one  
> of those.  You should have found every single help page.
>
> I don't see anything there that suggests it does a search through  
> the usage section.  Are you just making stuff up?

Apparently. I was constructing a theory to explain why my search was  
taking so long and returning so many pages. With your clarification  
above I tried a somewhat more successful search. I clearly missed  
reading the Description paragraph. New strategy:

help.search("\\.\\.\\.")

There are only 15 or so hits (could be more or less depending on the  
composition of the library packages)  and among them is 'dotsMethods'.  
That looks like a useful page for this topic.  The number of hits  
would only be half as large if the author of the "labeling" package  
had not put "..." at the end of 8 of his help page titles.

Sorry for the noise.

-- David.


>> If I just search with a browser for "..." in "Introduction to R" I  
>> get
>> what I consider to be useful material.
>
> Yes.  Other ways that should work, but don't:
>
> - looking through the index to An Introduction to R.  (The index is  
> very weak.)  Same for the R Language Definition.
>
> - doing a Google search for "R ...".  Stupid Google.
>
> Other ways that do work:
>
> - Reading the tables of contents for An Introduction to R, or the R  
> Language Definition.
>
> - Reading those manuals.
>
> - ?"..." in R-devel, after I commit the changes I described.
>
> - Searching with grep through the source files named *.Rd or *.texi.  
> (For this you need to have the source installed.)
>
> I do think the help system is too fragmented, but I also believe it  
> is better than it used to be.  I am sure that people would make  
> false claims about it regardless of any improvements, and other  
> people would complain about any changes, so it's not a priority for  
> me to work on it any more.
>
> Duncan Murdoch
>
>

David Winsemius, MD
Alameda, CA, USA