- id
A column that can be nested, ranging from 1 to 20.
- id2
Another column that can be nested, ranging from 1 to 10.
- x
A numeric column that depends on 'id'.
- y
A sequential numeric column (with some added randomness),
independent of the other columns.
- z
A column dependent on id, id2, x and y.
- a
A randomly generated numeric column, ranging from 1 to 100.
- b
A randomly generated numeric column, centred around 50.