Singular in MuMIn::dredge

Question

I'm about to run a glm model to test my hypothesis. Once I ran the model I got a singularity warning massage: glmakde_mdDredge <- lmer(log(akdearea) ~ 1 + age_binary + sex + trimester_number + Year + trackNightnum + mean_max_displacement.s + meanIIV_md.s + (1|Ring_ID), data = HRfullData, REML = F)

boundary (singular) fit: see ?isSingular

I ran MuMIn::dredge on this model

options(na.action = 'na.fail')
dreModelsScore <- MuMIn::dredge(glmakde_mdDredge)


Fixed term is "(Intercept)"
boundary (singular) fit: see ?isSingular
boundary (singular) fit: see ?isSingular
boundary (singular) fit: see ?isSingular

Summary did give results.

My question is whether despite the warning messages the model ran all the possible options (including the singularity ones) or only on the models where there is no singularity problem?

Answer 1

If a fitting function gives only a warning, and the value is a valid model object, it is included in the result (usually such models have suspicious likelihood or coefficient values). You can convert warnings to errors with option(warn = 2) which will exclude from the dredge result fits by which a warning was issued.