[R] Sorting problem

Duncan Murdoch murdoch at stats.uwo.ca
Sun Mar 29 20:51:30 CEST 2009


On 29/03/2009 2:14 PM, Stavros Macrakis wrote:
> On Sun, Mar 29, 2009 at 6:15 AM, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
>> On 28/03/2009 4:57 PM, Stavros Macrakis wrote:
>>> On Sat, Mar 28, 2009 at 7:53 AM, Duncan Murdoch <murdoch at stats.uwo.ca>
>>> wrote:
>>> 1) Where does the name 'xtfrm' come from?
>> I don't know.
> 
> Hmm.  If the origins of the name are lost in the mists of history,

I'm flattered, but I feel obliged to point out that just because I don't 
know something doesn't mean the information does not exist.

Duncan Murdoch

> perhaps a more mnemonic/intuitive one could be found?
> 
>>> 2) Why isn't xtfrm of a numeric vector the identity function?
>> "Because the implementation does that".  It's a one liner:...
> 
> Yes, I was asking *why* the implementation does that.
> 
>> The identity function would probably be faster, but why optimize cases that are never needed?
>> A better optimization would be just to use order(x), not order(xtfrm(x)).
> 
> Why should the *calling* function have the burden of type dispatching?




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