[R] Improvement: function cut

[Andrew Simmons]

While it is not explicitly mentioned anywhere in the documentation for
.bincode, I suspect 'include.lowest = FALSE' is the default to keep the
definitions of the bins consistent. For example:


x <- 0:20
breaks1 <- seq.int(0, 16, 4)
breaks2 <- seq.int(0, 20, 4)
cbind(
    .bincode(x, breaks1, right = FALSE, include.lowest = TRUE),
    .bincode(x, breaks2, right = FALSE, include.lowest = TRUE)
)


by having 'include.lowest = TRUE' with different ends, you can get
inconsistent behaviour. While this probably wouldn't be an issue with
'real' data, this would seem like something you'd want to avoid by default.
The definitions of the bins are


[0, 4)
[4, 8)
[8, 12)
[12, 16]


and


[0, 4)
[4, 8)
[8, 12)
[12, 16)
[16, 20]


so you can see where the inconsistent behaviour comes from. You might be
able to get R-core to add argument 'warn', but probably not to change the
default of 'include.lowest'. I hope this helps


On Fri, Sep 17, 2021 at 6:01 PM Leonard Mada <leo.mada using syonic.eu> wrote:

> Thank you Andrew.
>
>
> Is there any reason not to make: include.lowest = TRUE the default?
>
>
> Regarding the NA:
>
> The user still has to suspect that some values were not included and run
> that test.
>
>
> Leonard
>
>
> On 9/18/2021 12:53 AM, Andrew Simmons wrote:
>
> Regarding your first point, argument 'include.lowest' already handles this
> specific case, see ?.bincode
>
> Your second point, maybe it could be helpful, but since both 'cut.default'
> and '.bincode' return NA if a value isn't within a bin, you could make
> something like this on your own.
> Might be worth pitching to R-bugs on the wishlist.
>
>
>
> On Fri, Sep 17, 2021, 17:45 Leonard Mada via R-help <r-help using r-project.org>
> wrote:
>
>> Hello List members,
>>
>>
>> the following improvements would be useful for function cut (and
>> .bincode):
>>
>>
>> 1.) Argument: Include extremes
>> extremes = TRUE
>> if(right == FALSE) {
>>     # include also right for last interval;
>> } else {
>>     # include also left for first interval;
>> }
>>
>>
>> 2.) Argument: warn = TRUE
>>
>> Warn if any values are not included in the intervals.
>>
>>
>> Motivation:
>> - reduce risk of errors when using function cut();
>>
>>
>> Sincerely,
>>
>>
>> Leonard
>>
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>>
>

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