Example dataframe for input categorical data with structural zeros (with missing values). It contains 1000 observations and 5 variables.
| [,1] | AGEP | age | 7 levels |
| [,2] | MAR | marital status | 5 levels |
| [,3] | SCHL | educational attainment | 9 levels |
| [,4] | SEX | sex | 2 levels |
| [,5] | WKL | When last worked | 3 levels |