[R-sig-ME] [FORGED] warning error question

[Salvador SANCHEZ COLON]

Dear Profr. Bolker,


Thanks so much for your intervention. In my view, what is really shameful is this sort of bullying, unnecesarily rude, offensive responses. If I would feel that it would be a waste of my precious time to respond to a silly, trivial or ill posed question, nobody obliges me to respond...but there is no need either for me to send out a rude, patronizing raprimend. What if the problem stems from our having to cope not only with a complex statistical issue, but also the foreign language barrier?


With all due respect.


Salvador SÁNCHEZ-COLÓN






En Lun, 23 Marzo, 2020 en 18:51, Ben Bolker <bbolker using gmail.com> escribió:
 

Para: r-sig-mixed-models using r-project.org


On 2020-03-23 6:33 p.m., Rolf Turner wrote:
> 
> On 24/03/20 3:41 am, Anahí Fernández wrote:
> 
>> hi!! I run this model in lme4:
>> "M.4=glm(Cuenta~carga*categ.asoc+(1|campo/foto)
>>            +offset(log(area.foto)),family=poisson(link =
>> "log"),data=tipocat)"
>> And I have this warning message: "Warning message:
>> In checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv,  :
>>    Model failed to converge with max|grad| = 0.00432818 (tol = 0.001,
>> component 1)"
>> I don´t know what is that means, could you help me, please!!
>> My datatable is attached...
>>
>> Cheers, Anahí
> 
> (a) Since the function you invoke is glm() this would appear to be
> off-topic for r-sig-mixed-models.  OTOH your formula does indeed seem to
> involve random effects.  Did you *really* call glm()?  Or did you
> actually call glmer()?  If so you, you should be ashamed of yourself for
> such sloppiness in posing your question.  People are providing help out
> of the goodness of their hearts; don't impose on their good nature by
> expecting them to be telepathic.

Rolf, can you tone it down slightly? I agree that the OP could be more
careful, but "you should be ashamed of yourself" seems way too strong.

> (b) Assuming that you really did call glmer() --- my impression is that
> such warnings are usually false positives and may usually (???) be
> safely (???) ignored.  However I'm no expert; you should perhaps wait
> for confirmation of this from the more knowledgeable.
> 
> (c) Your "datatable" was *NOT* attached.  Most attachments get stripped
> by the system (for security reasons).  There are exceptions.  *READ* the
> posting guide, which you appear not to have done.

I did get the data from a previous interchange (Anahí, can you post
the data set somewhere publicly accessible? CSV is strongly preferred
to XLSX ...).

The bottom line here is that your baseline category has only a single
'Cuenta' value in it and only two unique 'carga' values, leading to
extreme estimates - this is essentially the analogue of 'complete
separation' in the logistic regression, and has the same solutions
(regularize somehow if you want sensible answers).

cheers
Ben Bolker


Cuenta
categ.asoc 1 2 3 4 5 6 7 8 9
highly 10 0 0 0 0 0 0 0 0
isolated 78 20 8 4 1 0 1 0 0
moderately 58 0 1 0 0 0 0 0 0
poorly 120 47 24 16 12 9 0 1 1

round(coef(summary(M.4)),3)
Estimate Std. Error z value Pr(>|z|)
(Intercept) -2.852 1.264 -2.257 0.024
carga 8.029 13.626 0.589 0.556
categ.asocisolated 1.776 1.255 1.415 0.157
categ.asocmoderately 1.299 1.256 1.034 0.301
categ.asocpoorly 1.929 1.251 1.542 0.123
carga:categ.asocisolated -9.548 13.612 -0.701 0.483
carga:categ.asocmoderately -9.418 13.614 -0.692 0.489
carga:categ.asocpoorly -9.006 13.615 -0.661 0.508

> 
> cheers,
> 
> Rolf Turner
>

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