| interaction {base} | R Documentation |
Compute Factor Interactions
Description
interaction computes a factor which represents the interaction
of the given factors. The result of interaction is always unordered.
Usage
interaction(..., drop = FALSE)
Arguments
... |
the factors for which interaction is to be computed, or a single list giving those factors. |
drop |
if |
Value
A factor which represents the interaction of the given factors.
The levels are labelled as the levels of the individual factors joined
by ..
References
Chambers, J. M. and Hastie, T. J. (1992) Statistical Models in S. Wadsworth \& Brooks/Cole.
See Also
factor, :
Examples
a <- gl(2, 2, 8)
b <- gl(2, 4, 8)
interaction(a, b)