I am trying to fit a mixed model using the library lme4, and is emerging the following error.
fixed-effect model matrix is rank deficient so dropping 10 columns / coefficients.
In this case, I'm using the Effects window and time as factors. If they are considered numeric, the error becomes
fixed-effect model matrix is rank deficient so dropping 2 columns / coefficients.
Follow the syntax used.
Modelo1 <-lmer (EREF GROUP ~ + Time + window + GROUP:Time + GROUP:Window + Time:Window + Time:Window:GROUP + (1 | Subject), data = datalong2)
From what I see, it is not estimating doi elements of interaction between GROUP: WINDOW.
Does anyone have suggestions to solve this problem?