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Sorry that this error has been discussed before, each answer on stackoverflow seems specific to the data

I'm attempting to run the following negative binomial model in lme4:

Model5.binomial<-glmer.nb(countvariable ~ waves + var1 + dummycodedvar2 + dummycodedvar3 + (1|record_id), data=datadfomit) 

However, I receive the following error when attempting to run the model:

Error in f_refitNB(lastfit, theta = exp(t), control = control) :pwrssUpdate did not converge in (maxit) iterations

I first ran the model with only 3 predictor variables (waves, var1, dummycodedvar2) and got the same error. But centering the predictors fixed this problem and the model ran fine.

Now with 4 variables (all centered) I expected the model to run smoothly, but receive the error again.

Since every answer on this site seems to point towards a problem in the data, data that replicates the problem can be found here:

https://file.io/3vtX9RwMJ6LF
JustinB
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    the URL above takes me to a "this file has been deleted" banner. I would be interested in digging into this, but would also suggest trying `glmmTMB` ... – Ben Bolker Apr 01 '22 at 21:05
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    @BenBolker Holy crap your suggestion works so well! Model runs perfectly as far as I can tell, as well as super quickly compared to lme4. Any explanation on why? If you're still interested in digging: Sorry for the dead link. Hope this works: https://ufile.io/km1p57bo – JustinB Apr 02 '22 at 15:33

1 Answers1

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Your response variable has a lot of zeros:

enter image description here

I would suggest fitting a model that takes account of this, such as a zero-inflated model. The GLMMadaptive package can fit zero-inflated negative binomial mixed effects models:

## library(GLMMadaptive)
## mixed_model(countvariable ~ waves + var1 + dummycodedvar2 + dummycodedvar3, ##   random = ~ 1 | record_id, data = data,
##   family = zi.negative.binomial(), 
##   zi_fixed = ~ var1,
##   zi_random = ~ 1 | record_id) %>% summary()

Random effects covariance matrix:
                StdDev    Corr
(Intercept)     0.8029        
zi_(Intercept)  1.0607 -0.7287

Fixed effects:
               Estimate Std.Err z-value  p-value
(Intercept)      1.4923  0.1892  7.8870  < 1e-04
waves           -0.0091  0.0366 -0.2492 0.803222
var1             0.2102  0.0950  2.2130 0.026898
dummycodedvar2  -0.6956  0.1702 -4.0870  < 1e-04
dummycodedvar3  -0.1746  0.1523 -1.1468 0.251451

Zero-part coefficients:
            Estimate Std.Err z-value    p-value
(Intercept)   1.8726  0.1284 14.5856    < 1e-04
var1         -0.3451  0.1041 -3.3139 0.00091993

log(dispersion) parameter:
  Estimate Std.Err
    0.4942  0.2859

Integration:
method: adaptive Gauss-Hermite quadrature rule
quadrature points: 11

Optimization:
method: hybrid EM and quasi-Newton
converged: TRUE 
Robert Long
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