[Rd] head/tail breaking change

[Jan Gorecki]

Thank you Gabriel,
I agree that new behaviour makes much more sense. Just wanted to confirm
before resolving compatibility of my unit tests.
Best,
Jan

On Wed 18 Dec, 2019, 10:46 PM Gabriel Becker, <gabembecker using gmail.com> wrote:

> Jan,
>
> That is an intentional change as you can see in the documentation for
> head/tail in R-devel. Last time I discussed it with Martin, this behavior
> was desired and thus is unlikely to change unless "our" (ie his) mind does.
>
> The hope is that the new behavior is actually what people would want (note
> it already behaves this way for data.frames and for matrices, which are now
> explicitly array objects with 2 dimensions as well as classed as matrices,
> so its more consistent now, and more reasonable for the object).
>
> Best,
> ~G
>
> On Wed, Dec 18, 2019 at 2:44 AM Jan Gorecki <j.gorecki using wit.edu.pl> wrote:
>
>> Hi R-devel community,
>>
>> I am aware of changes in R-devel in head/tail methods but I was not
>> expecting that to be a breaking change.
>>
>> # R 3.6.1
>> ar = array(1:27, c(3,3,3))
>> tail(ar, 1)
>> #[1] 27
>>
>> The current output of R-devel is something that I would expect from a
>>
>> tail(ar, c(1, Inf, Inf))
>>
>> or
>>
>> tail(ar, c(1, NA, NA))
>>
>> calls.
>> Is it going to stay like this or there are plans to mitigate this
>> breaking change?
>>
>> # R-devel 2019-12-17 r77592
>> ar = array(1:27, c(3,3,3))
>> tail(ar, 1)
>> #, , 1
>> #
>> #     [,1] [,2] [,3]
>> #[3,]    3    6    9
>> #
>> #, , 2
>> #
>> #     [,1] [,2] [,3]
>> #[3,]   12   15   18
>> #
>> #, , 3
>> #
>> #     [,1] [,2] [,3]
>> #[3,]   21   24   27
>>
>> Best,
>> Jan Gorecki
>>
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>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>

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