why do gamm models use mixture do you need a mixture model for a variable what to use for the omitted variable in a mixture model what model is used to compensate for an omitted variable why do you use a mixture model what model would you use for omitted variables why use a mixture modelling when to use mixture models in r can you use gamm for omitted variable how to use mixture model what is the purpose of gamm r what is mixed model for what type of model would i use to compensate for an omitted variable what type of model to use to compensate for an omitted variable which model is best for omitted variables why use gamm can gamm be used to fit a categorical variable can gamm model compensate for categorical variable? what is the function in a mixture model can you use a gamm mixture model