Compute the Interaction of Several Factors
DESCRIPTION:
Computes the interaction of several factors and returns a new factor with
levels that represent all combinations of the factors supplied as
arguments.
USAGE:
interaction(design, drop = F)
interaction(..., drop = F)
REQUIRED ARGUMENTS:
- design
-
- ...
-
the arguments to
interaction
can be either a data frame containing
all the factors to be used
orall the individual factors.
It will not understand a combination of factors and designs as arguments;
you have to pick one form or the other.
OPTIONAL ARGUMENTS:
- drop
-
if
TRUE
the levels of the new factor not represented in the data are dropped.
VALUE:
a new factor, whose levels are all possible combinations of the factors
supplied as arguments. If
drop = T
, only the levels represented in the
new factor are retained.
EXAMPLES:
attach(catalyst)
Temp
[1] 160 180 160 180 160 180 160 180
Conc
[1] 20 20 40 40 20 20 40 40
interaction(Temp, Conc)
[1] 160.20 180.20 160.40 180.40 160.20 180.20 160.40 180.40