In lme4/lme4: Linear Mixed-Effects Models using 'Eigen' and S4

I guess lme4 might have some magic to temporarily suppress the warnings in summary() so withCallingHandlers() is unable to catch them. I looked at the source code of lme4 for a while, but did not figure out whether or how they did it. Here is a reproducible example that you should report to https://github.com/lme4/lme4/issues (ping @bbolker or @mmaechler or someone in the dev team):

A simpler example than the one presented:

library("lme4")
ss <- transform(sleepstudy,obs=factor(1:nrow(sleepstudy)))

Regular run produces a warning:

m1 <- lmer(Reaction~1+(1|obs),data=ss,
     control=lmerControl(check.nobs.vs.nlev="warning",
                         check.nobs.vs.nRE="ignore"))

Running inside summary() doesn't:

sum1 <- summary(m1 <- lmer(Reaction~1+(1|obs),data=ss,
     control=lmerControl(check.nobs.vs.nlev="warning",
                         check.nobs.vs.nRE="ignore")))

BUT this is the same behaviour as base-R functions!

sqrt() produces a warning in this case:

sq <- sqrt(-1)

... but if we nest inside summary() it doesn't!

summary(sq <- sqrt(-1))

lme4/lme4 documentation built on April 24, 2024, 5:51 p.m.