[R] question on function arguments

[baptiste Auguié]

any input?

(and also, why would all my posts get bounced off while I clearly  
subscribed to this list?)

Best regards,


On 18 Feb 2008, at 09:53, baptiste Auguié wrote:

> Hi,
>
> I have two small issues with my R code, no big deal but curiosity
> really. Here is a sample code,
>
>
>>
>> x <- rnorm(1:10)
>>
>> foo <- function(a = 1, b = list(x = c(1:10), y = c(1:10))){
>> 	
>> 	for (ii in seq(along=b$y)){
>> 		
>> 		print(x[ii] + b$x[ii])
>> 	}
>> 	
>> 	
>> }
>>
>> foo() # default OK
>>
>> foo(b=list(x=1, y=c(1:10))) # only the first term works
>>
>> foo(b$y = 1:5) # error
>>
>
> In the last call, i wish to use all default arguments but b$y (that
> is, using the default a and b$x). Is this possible?
>
> The second call is more related to indices: i would like my argument b
> $x to be either a vector (default), or a scalar. In the latter, the
> loop b$x[ii] breaks when i would like it to recycle the single value.
> I can check the length of b$x with a "if" statement, but it becomes
> intricate when several arguments have this option of being vector or
> scalar. Is there a way to use b$x that would work in both cases?
>
>
> Many thanks,
>
> baptiste
>
> _____________________________
>
> Baptiste Auguié
>
> Physics Department
> University of Exeter
> Stocker Road,
> Exeter, Devon,
> EX4 4QL, UK
>
> Phone: +44 1392 264187
>
> http://newton.ex.ac.uk/research/emag
> http://projects.ex.ac.uk/atto
>
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