Get key set stored with a confrontation
keyset(x)# S4 method for confrontation
keyset(x)
If a confrontation is created with the key= option
set, this function returns the key set, otherwise NULL
an object of class confrontation
Other confrontation-methods:
[,expressionset-method,
as.data.frame,confrontation-method,
confront(),
confrontation-class,
errors(),
event(),
length,expressionset-method,
values()