[R-sig-ME] What does that mean?

[Ben Bolker]

On 2019-04-29 8:09 p.m., DESPINA MICHAILIDOU wrote:
> I am trying to run the following analysis and receive the following output
> 
> glmm_Comb_PH_tod <- glmer(Comb_PH_tod~ CA_effect + (1 | ID/SCAN_DATE/Side),
> data=TAK_data, family=binomial(link = "logit"))
> summary(glmm_Comb_PH_tod)
> 
> Output
> Error in length(value <- as.numeric(value)) == 1L :
>   (maxstephalfit) PIRLS step-halvings failed to reduce deviance in
> pwrssUpdate
>> summary(glmm_Comb_PH_tod)
> Error in summary(glmm_Comb_PH_tod) : object 'glmm_Comb_PH_tod' not found
> 
> How can I fix that? Any suggestions? I am very new to R.
> 
> Thank you in advance.
> Despina

  The second error is relatively easy to understand; since your first
command (using glmer(...)) didn't work, no object "glmm_Comb_PH_tod" has
been created for you to summarize.

  The first part is harder.  My guess would be that there's complete
separation ; I've added a few more notes about the "PIRLS step-halving"
error to the GLMM FAQ
<http://bbolker.github.io/mixedmodels-misc/glmmFAQ.html>.  But it's hard
to know without seeing the actual data.