This function is intended to be used with
sim_agg and not interactively. This is one implementation for aggregating data in a simulation set-up.
agg_all(groupVars = "idD")
variable names as character identifying groups to be aggregated.
This function follows the split-apply-combine idiom. Each data set is split by the defined variables. Then the variables within each subset are aggregated (reduced to one row). Logical variables are reduced by
any; for characters and factors dummy variables are created and the aggregate is the mean of each dummy; and for numerics the mean (removing NAs).