[R] Default parameter values in R functions?

[Marc Schwartz]

Just to point out another reference, which is the R Language Definition, where in section 4.3.2:

  http://cran.r-project.org/doc/manuals/R-lang.html#Argument-matching

entitled "Argument Matching", there are some pointers to the use of match.arg(), leading you to the help page pointed to by Bert and Michael. It also makes note that this applies to "closures", but not to "primitives" where the handling of arguments is different. 

Regards,

Marc Schwartz

On Apr 2, 2012, at 4:59 PM, Michael wrote:

> Okay! Thank you both for your help!
> 
> So it chooses the 1st one by default...
> 
> Thank you!
> 
> On Mon, Apr 2, 2012 at 4:43 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> 
>> Yes, it's a bit subtle.
>> 
>> Argument matching is usually done through match.arg(), so see
>> ?match.arg
>> for an explanation..
>> (the first chosen).
>> -- Bert
>> 
>> 
>> On Mon, Apr 2, 2012 at 2:30 PM, Michael <comtech.usa at gmail.com> wrote:
>>> Hi all,
>>> 
>>> I have a newbie question:
>>> 
>>> If I have a function with the following documentation:
>>> 
>>> 
>>> ca.jo(x, type = c("eigen", "trace"), ecdet = c("none", "const",
>> "trend"), K = 2,
>>> spec=c("longrun", "transitory"), season = NULL, dumvar = NULL)
>>> 
>>> Let's take "type" as an example... if I omit this parameter when
>>> calling the function,
>>> 
>>> 
>>> 
>>> what's going to be the default value for this parameter?
>>> 
>>> 
>>> 
>>> Amazingly the documentation didn't say which one is the default...
>>> 
>>> Thank you!
>>> 
>>>       [[alternative HTML version deleted]]
>>> 
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
>>> and provide commented, minimal, self-contained, reproducible code.
>> 
>> 
>> 
>> --
>> 
>> Bert Gunter
>> Genentech Nonclinical Biostatistics
>> 
>> Internal Contact Info:
>> Phone: 467-7374
>> Website:
>> 
>> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm
>> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.