[R] Custom Numeric type in R

[Duncan Murdoch]

On 13-11-10 4:52 PM, Rui Barradas wrote:
> Hello,
>
> Try the following.
>
>   > class(NA)
> [1] "logical"

This doesn't actually prove anything, since there are multiple different 
objects that display as NA.  For example:

 > 1+NA
[1] NA
 > class(1+NA)
[1] "numeric"

See ?"NA" for other ways to represent the other NA values.


>   > class(NaN)
> [1] "numeric"
>   > class(Inf)
> [1] "numeric"
>
>
> So my guess is that what the op wants is not possible. And that to
> declare a new class shouldn't solve the problem.

I don't think it is impossible, but I think it would be hard to get it 
working well.

Duncan Murdoch

>
> Rui Barradas
>
> Em 10-11-2013 21:07, Bert Gunter escreveu:
>> Charles:
>>
>> That was my initial thought, too. But then I wondered whether what was
>> meant was to use "TBD" as an alternative kind of numeric value that
>> would be part of numeric vectors, lists, etc.  in the same way that NA
>> or Inf is. It is not clear to me that a new object class provides a
>> way to do this, at least not without a large amount of recreating
>> standard R objects and the operations on them to include a "TBD" type
>> numeric. My understanding is that NA and Inf are built into R's
>> internals as part of IEEE floating point standards. I do not know how
>> or if one can add new numeric types to these.
>>
>> I would appreciate correction of any misunderstanding that I have and
>> further details as to how one would do this.
>>
>> Best,
>> Bert
>>
>> On Sun, Nov 10, 2013 at 9:49 AM, Charles Berry <ccberry at ucsd.edu> wrote:
>>> Christofer Bogaso <bogaso.christofer <at> gmail.com> writes:
>>>
>>>>
>>>> Hi again,
>>>>
>>>> In R, there are various numerics like, NA, Inf, or simple integers etc.
>>>> However I want to include one custom type: "TBD", which R should treat as
>>>> numeric, not character.
>>>>
>>>> That "TBD" should have same property like Inf, however except this: TBD -
>>>> TBD = 0
>>>>
>>>> In future, I am planning to add few more properties to TBD.
>>>>
>>>> Can somebody guide me if this is possible in R, ans also some pointer on
>>>> how can be done in R
>>>>
>>>
>>> Possible? Yes.
>>>
>>> Your question might be framed as
>>>
>>> "How do I create a class and write a method for '-' that does ... ?"
>>>
>>> The answer is "learn about methods and classes in R".
>>>
>>> To get started, see
>>>
>>>    ?methods
>>>    ?class
>>>    ?groupGenericFunction-class
>>>    ?groupGeneric
>>>
>>> and follow the links therein.
>>>
>>>
>>> Check the posting guide. If you need to follow up, you should consider
>>> whether the question you have fits better on R-devel.
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>