Dear all, I am trying to reproduce the exemple in the vignette "Using lme4 to fit Generalized Additive Mixed Models" with my dataset. But... > mod <- amer(pasvig ~ -1 + harvf + tp(dias,by=harvf) + (1 | pac), data=exemplo) Erro em if (from == to) rep.int(from, length.out) else as.vector(c(from, : valor ausente onde TRUE/FALSE necess?rio A subset of the dataset is attached. No clue about what is wrong. Thanks a lot! Marilia