[Rd] Historical NA question

[Hervé Pagès]

On 05/06/2014 12:36 PM, William Dunlap wrote:
> When does els%in%set give a different result than is.element(els,set)?
>   I assumed they were copied form S+, where they are the same except
> for argument names, but I may be wrong.

   > els <- 2:1
   > set <- 1:6
   > - els%in%set
   [1] FALSE FALSE
   > - is.element(els,set)
   [1] -1 -1

So following your advice doesn't really help me leave my precedence
problems behind.

H.

> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
>
> On Tue, May 6, 2014 at 12:23 PM, Hervé Pagès <hpages at fhcrc.org> wrote:
>> On 05/06/2014 08:54 AM, William Dunlap wrote:
>>>
>>> You can also use is.element(els,set) instead of the equivalent
>>> els%in%set
>>
>>
>> No they are not *equivalent*. Equivalent means you could substitute
>> one by the other in your code without changing its behavior.
>>
>> H.
>>
>>> and leave your precedence problems behind.
>>> Bill Dunlap
>>> TIBCO Software
>>> wdunlap tibco.com
>>>
>>>
>>> On Mon, May 5, 2014 at 10:35 PM, peter dalgaard <pdalgd at gmail.com> wrote:
>>>>
>>>>
>>>> On 06 May 2014, at 01:05 , Hervé Pagès <hpages at fhcrc.org> wrote:
>>>>
>>>>>
>>>>> BTW, that %in% has precedence over arithmetic operations is surprising,
>>>>> error-prone, and doesn't cover any reasonable use case (who needs to
>>>>> multiply the logical vector returned by %in% by some value?) but that's
>>>>> another story:
>>>>
>>>>
>>>> The point here is that the %foo% operators all have the _same_
>>>> precedence. In principle, they can be user-coded, and there is no way to
>>>> express what precedence is desirable. It may turn out slightly weird for
>>>> %in%, but think of what would happen if %*% had lower precedence than
>>>> addition.
>>>>
>>>> --
>>>> Peter Dalgaard, Professor,
>>>> Center for Statistics, Copenhagen Business School
>>>> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
>>>> Phone: (+45)38153501
>>>> Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com
>>>>
>>>> ______________________________________________
>>>> R-devel at r-project.org mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>>
>> --
>> Hervé Pagès
>>
>> Program in Computational Biology
>> Division of Public Health Sciences
>> Fred Hutchinson Cancer Research Center
>> 1100 Fairview Ave. N, M1-B514
>> P.O. Box 19024
>> Seattle, WA 98109-1024
>>
>> E-mail: hpages at fhcrc.org
>> Phone:  (206) 667-5791
>> Fax:    (206) 667-1319

-- 
Hervé Pagès

Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024

E-mail: hpages at fhcrc.org
Phone:  (206) 667-5791
Fax:    (206) 667-1319