[R] Fwd: Potential Issue with lm.influence

[Bert Gunter]

I told you already: **Include code inline **

See ?dput for how to include a text version of objects, such as data
frames, inline.

Otherwise, I believe .txt text files are not stripped if you insist on
*attaching* data or code. Others may have better advice.


Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Tue, Apr 2, 2019 at 1:21 PM Eric Bridgeford <ericwb95 using gmail.com> wrote:

> How can I add attachments? The following two files were attached in the
> initial message
>
> On Tue, Apr 2, 2019 at 3:34 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
>
>> Nothing was attached. The r-help server strips most attachments. Include
>> your code inline.
>>
>> Also note that
>>
>> > 0/0
>> [1] NaN
>>
>> so maybe something like that occurs in the course of your calculations.
>> But that's just a guess, so feel free to disregard.
>>
>>
>> Bert Gunter
>>
>> "The trouble with having an open mind is that people keep coming along
>> and sticking things into it."
>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>
>>
>> On Tue, Apr 2, 2019 at 11:32 AM Eric Bridgeford <ericwb95 using gmail.com>
>> wrote:
>>
>>> Hi R core team,
>>>
>>> I experienced the following issue with the attached data/code snippet,
>>> where the studentized residual for a single observation appears to be NaN
>>> given finite predictors/responses, which appears to be driven by the
>>> glm.influence method in the stats package. I am curious to whether this
>>> is
>>> a consequence of the specific implementation used for computing the
>>> influence, which it would appear is the driving force for the NaN
>>> influence
>>> for the point, that I was ultimately able to trace back through the
>>> lm.influence method to this specific line
>>> <
>>> https://github.com/SurajGupta/r-source/blob/a28e609e72ed7c47f6ddfbb86c85279a0750f0b7/src/library/stats/R/lm.influence.R#L67
>>> >
>>> which
>>> calls C code which calls iminfl.f
>>> <
>>> https://github.com/SurajGupta/r-source/blob/master/src/library/stats/src/lminfl.f
>>> >
>>> (I
>>> don't know fortran so I can't debug further). My understanding is that
>>> the
>>> specific issue would have to do with the leave-one-out variance estimate
>>> associated with this particular point, which it seems based on my
>>> understanding should be finite given finite predictors/responses. Let me
>>> know. Thanks!
>>>
>>> Sincerely,
>>>
>>> --
>>> Eric Bridgeford
>>> ericwb.me
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>
> --
> Eric Bridgeford
> ericwb.me
>

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