get data from the currently loaded Selected Set in NASIS or from the entire local database (default: TRUE)
stringsAsFactors
logical: should character vectors be converted to factors? This argument is passed to the uncode() function. It does not convert those vectors that have set outside of uncode() (i.e. hard coded). The 'factory-fresh' default is TRUE, but this can be changed by setting options(stringsAsFactors = FALSE)