[R] Unexpected behavior with abbreviation of an argument to paste

[David Winsemius]

On Jan 27, 2013, at 4:10 PM, Dennis Fisher wrote:

> R 2.15.1
> OS X
>
> Colleagues,
>
> I encountered the following unexpected behavior today:
>
> The following command yielded the expected result:
> 	paste(c("TEXT1", "TEXT2"), collapse="|")
> Result:
> 	[1] "TEXT1|TEXT2"
>
> However, abbreviating "collapse" by even one character:
> 	paste(c("TEXT1", "TEXT2"), collaps="|")
> yielded the following:
> 	[1] "TEXT1 |" "TEXT2 |" >
>
> My experience has been that one can abbreviate these options as long  
> as there is no ambiguity.  For example, the "ignore.case" argument  
> for grep can be abbreviated to "ig" (shortening it to a single  
> character creates an ambiguity).
>
> Is there something special about "collapse" that I am missing?

What you are missing is not special about 'collapse', but is rather a  
feature shared by any argument after the "dots" in a function's  
argument list.

-- 

David Winsemius, MD
Alameda, CA, USA