A list with two components.
tab - a data frame with the following information about each variable:
- name
variable name
- class
class of variable
- nmiss
number of missing values (NA)
- perctmiss
percentage of missing values
- ndistinct
number of distinct values (excluding missing values)
- details
range for numeric variables, maximum length for character
variables, labels for factors with <= maxlevs levels
labs - a list of extra tables with labels for each factor with number
of levels greater than maxlevs.