[Rd] as.character on NaN gives "NaN", is that intentional?

Ulrike Grömping groemping at bht-berlin.de
Tue Sep 7 21:18:58 CEST 2010


Kevin,

I wouldn't mind NaN (although it seems a bit strange, because you 
wouldn't expect a character to be a number), but I find it strange to 
get the character string "NaN". is.na(as.character(NaN)) returns FALSE, 
which is what I dislike.

Best, Ulrike

Kevin R. Coombes schrieb:
>  It seems to me that preserving information about the kind of number 
> (or not) present would be useful. I rather like the fact that
>    as.numeric(as.character(NaN))
> and
>    as.numeric(as.character(Inf))
> both work as the identity operator on numeric-like objects.  (In this 
> context, note that both is.numeric(NaN) and is.numeric(Inf) both 
> return TRUE.)  In your example, the character string "ee" does not 
> represent any number that I know about (at least in standard R).
>
>     Kevin
>
> On 9/7/2010 11:23 AM, Ulrike Grömping wrote:
>> Dear DevelopeRs,
>>
>> I am surprised about the outcome of the second command:
>>
>> str(as.character(as.numeric("ee"))) str(as.character(log(-1)))
>>
>> I would have expected a character NA. Is there an intention behind 
>> this behavior?
>>
>> Best, Ulrike
>>



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