[R-SIG-Mac] ?if

Dr. John R. Vokey vokey at uleth.ca
Sun Feb 13 04:09:15 CET 2005


I am trying to introduce a class of senior undergraduates to the values 
and advantages of R for their statistical needs.  Unfortunately, little 
(and inconsequential) inconsistencies such as these do little to 
improve their confidence in the application.  It is not that I needed 
help on the topics, but my students may, and when the two tools they 
know how to use, ? and apropos(), fail, I get panicked e-mails...  I 
just thought the list would want to know.

-John


On 12-Feb-05, at 7:47 PM, Rob J Goedman wrote:

> Thanks Byron.
>
> You're right. In fact ?"if" works fine as well.
>
> You do have the November version of R.app. The R.app on Simon's site 
> will give you a faster
> response if it can't find help on a topic.
>
> Rob
>
> On Feb 12, 2005, at 5:04 PM, Dr. John R. Vokey wrote:
>
>> help(if) (or other control control structures aside from if) gives 
>> the same non-result, unless quoted (as noted).  A related error 
>> occurs with apropos(if)---it returns a syntax error.
>>
>> The version is: This version:
>> 	Version 1.01
>>
>> Requires:
>> 	R  2.0.1 (2004-11-15)
>> 	Framework Version
>>
>>
>> On 12-Feb-05, at 5:40 PM, Byron Ellis wrote:
>>
>>> Actually there is help for control structures, help("if") works just 
>>> fine. The problem is ? is that R's parser treats ? as an operator 
>>> with unary and binary forms when, in fact, its not really an 
>>> operator. ?if(TRUE) TRUE (any valid IF construct) will also give the 
>>> help for 'if'. This is true for all platforms and probably has 
>>> something to do with the fact that while "if" is bound directly to a 
>>> primitive ( "if"(runif(1) < 0.5,TRUE,FALSE) is equivalent to 
>>> if(runif(1) < 0.5) TRUE else FALSE) , the if bareword gets special 
>>> handling in the parser.
>>>
>>> On Feb 12, 2005, at 4:33 PM, Rob J Goedman wrote:
>>>
>>>> John,
>>>>
>>>> Just to make sure, which configuration are you using?
>>>>
>>>> Assuming the GUI (otherwise you would see a "+" instead of the ">" 
>>>> prompt), which version of
>>>> the R.app are you using? The creation date listed in Finder will do.
>>>>
>>>> I think you noticed 2 issues. Right now, there is no ? help for 
>>>> control structures. You have to go
>>>> to the language reference manual. Secondly, newer versions of R.app 
>>>> (just the GUI part, as
>>>> released by Simon on http://www.rosuda.org/R/nightly/ ) will tell 
>>>> you if there is no help for
>>>> the requested topic.
>>>>
>>>> Hope this helps,
>>>> Rob
>>>>
>>>>
>>>> On Feb 12, 2005, at 1:22 PM, Dr. John R. Vokey wrote:
>>>>
>>>>> ? followed by any of the condition statements (or help() 
>>>>> containing the condition statement)  does nothing (i.e., the help 
>>>>> window fails to open), but the line is parsed in that the prompt 
>>>>> `>' is returned.  Is this a parsing error in the help function, or 
>>>>> (more likely) have I missed some deep R construct?
>>>>> --
>>>>> John
>>>>>
>>>>>
>>>>> --
>>>>> John R. Vokey, PhD
>>>>> Professor
>>>>> B.E.R.G. - Behaviour and Evolution Research Group
>>>>> Micro-Cognition Laboratory
>>>>> Department of Psychology & Neuroscience
>>>>> University of Lethbridge
>>>>> Lethbridge, Alberta T1K 3M4
>>>>> CANADA
>>>>>
>>>>> _______________________________________________
>>>>> R-SIG-Mac mailing list
>>>>> R-SIG-Mac at stat.math.ethz.ch
>>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>>>
>>>> _______________________________________________
>>>> R-SIG-Mac mailing list
>>>> R-SIG-Mac at stat.math.ethz.ch
>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>>>
>>> ---
>>> Byron Ellis (ellis at stat.harvard.edu)
>>> "Oook" -- The Librarian
>>>
>>>
>> --
>> John R. Vokey, PhD
>> Professor
>> B.E.R.G. - Behaviour and Evolution Research Group
>> Micro-Cognition Laboratory
>> Department of Psychology & Neuroscience
>> University of Lethbridge
>> Lethbridge, Alberta T1K 3M4
>> CANADA
>>
>
>



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