[Rd] by should use match.fun

Simon Urbanek simon.urbanek at r-project.org
Sun Jun 12 21:32:02 CEST 2005

On Jun 12, 2005, at 3:21 PM, Gabor Grothendieck wrote:

> On 6/12/05, Liaw, Andy <andy_liaw at merck.com> wrote:
>> I don't get the point.  ?by says:
> The point is that all other functions of this sort including apply,  
> sapply,
> tapply, lapply work like that so 'by' ought to as well.
> Here is the example (changed to use iris) where I noticed it.   
> Suppose we
> want to create a list of rows:
> by(iris, row.names(iris), "(")

Umm.. why don't you just use

by(iris, row.names(iris), `(`)

In general I consider passing functions as text unnecessary - the  
only use I could think of is constructing function names from strings/ 
data and I'm not sure that is a good idea, either (it causes quite  
some performance issues) ... just my 2 pennies ...


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