A data.table can be used in S4 class definitions as either a parent class (inside a contains argument of setClass), or as an element of an S4 slot.

See also

Examples

## Used in inheritance. setClass('SuperDataTable', contains='data.table') ## Used in a slot setClass('Something', representation(x='character', dt='data.table')) x <- new("Something", x='check', dt=data.table(a=1:10, b=11:20))