why nlme is the best mixed effects library to use? what is the lme library why use nlme r is lme better or nlme what library is better mixed effects which library to use for longitudinal modeling nlme vs lme4 what is the difference between nlme and lme4 why use nlme vs lme4 what is lme4 model what is r mixed effects which r library should i use for longitudinal data? what is nlme used for what is lme r model used for what is the nlme library lme library definition which r library is better mixed effects or nlme is lme4 or nlme2 better difference between r and nlme library difference between lme and nlme