Problem combining ranef plots of two models with grid.arrange()

Question

I have two LMEs:

lme1 <- lmer(F1 ~ (phoneme|individual) + (1|word) + frequency, 
         data = nurse_female)
lme2 <- lmer(F2 ~ (phoneme|individual) + (1|word) + 
                   frequency + age + (1|zduration), 
         data = nurse_female)

I created simple dotplots dotplot(ranef(lme1)) of the random effects which creates a plot for each random predictor. I am however only interested in the phoneme|individual one which looks like this:

Normally I would use grid.arrange() but I can't get it to only select the phoneme|individual plots. Do you know a way to do this?

Answer 1

(A reproducible example would be useful, I hope this example does what you want ...). I think the key here is to recognize that the dotplot.ranef.mer method returns a list of plots:

library(lme4)
fm1 <- lmer(angle ~ (1|recipe) + (1|recipe:replicate), cake, REML= FALSE)
dd <- dotplot(ranef(fm1))
length(dd) ## 2

They're not necessarily in the same order as in the formula:

names(dd) ## [1] "recipe:replicate" "recipe"          
print(dd[["recipe"]])
print(dd[["recipe:replicate"]])

So you would want something like

f <- function(m) dotplot(ranef(m))[["individual"]]
gridExtra::grid.arrange(f(lme1),f(lme2))