> mod <- glmer('categorical_FOD_FODs ~ Condition_FODs + Language_used_FODs + (1 | subject_FODs)', + data = indvar_FODs, family = binomial) boundary (singular) fit: see help('isSingular') write optimizer

f <- function(x) {
  return(x[1]^2 + x[2]^2)
}

optim(c(0,0), f) #returns: $par
#[1] 7.105427e-15 7.105427e-15
#$value
#[1] 1.110223e-16
#$counts
#function gradient 
#$convergence
#[1] 0
#$message
#NULL