[R] Mean error message missing

[Duncan Murdoch]

On 08/06/2015 6:04 AM, Christian Brandstätter wrote:
> Thank you for the explanation.
> But if you take for instance plot.default(), being another generic 
> function, it would not work like that:
> plot(1,2,3,4), only plot(1,2) is accepted.
> 
> 
>  From R-help (Usage):
> ## Default S3 method:
> mean(x, trim = 0, na.rm = FALSE, ...)
> 
> What is puzzling, is that apparently na.rm (and trim, which is indicated in the help) is accepting numeric values.
> mean(c(1,NA,10),10,TRUE)
> mean(c(1,NA,10),10,FALSE)
> 
> This should give at least a warning in my opinion.

It is a common idiom in R programming to treat non-zero values as TRUE,
and zero as FALSE.  If every use of a number where a logical is needed
generated a warning, you'd be swamped with them.

Duncan Murdoch

> 
> mean(c(1,NA,10),10,200)
> 
> 
> 
> On 08/06/2015 09:27, Achim Zeileis wrote:
> 
>> On Mon, 8 Jun 2015, Christian Brandst�tter wrote:
>>
>>> Dear list,
>>>
>>> I found an odd behavior of the mean function; it is allowed to do 
>>> something that you probably shouldn't:
>>> If you calculate mean() of a sequence of numbers (without declaring 
>>> them as vector), mean() then just computes mean() of the first 
>>> element. Is there a reason why there is no warning, like in sd for 
>>> example?
>>
>> mean() - unlike sd() - is a generic function that has a '...' argument 
>> that is passed on to its methods. The default method which is called 
>> in your example also has a '...' argument (because the generic has it) 
>> but doesn't use it.
>>
>>> Example code:
>>> mean(1,2,3,4)
>>> sd(1,2,3,4)
>>>
>>> Best regards
>>> Christian
>>>
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>>> http://www.R-project.org/posting-guide.html
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>>>
> 
> 
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> 
> 
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>