Use
formula() on a
design object
USAGE:
formula.design(object, multiy = T)
ARGUMENTS:
- object
-
any object inheriting from class
"design".
- multiy
-
if more than one non-factor is included in the design variables, should
the response be all these combined using
cbind(), or just the first one.
This is a method for the function
formula() for objects inheriting from class
design.
The variable(s) in the design which do not inherit from
"factor" are
candidates for the response.
Depending on
multiy, all or only the first will be used.
If
multiy is
FALSE, extra non-factors are not included in the formula;
that is, quantitative covariates are not included automatically.
See the example.
EXAMPLES:
sapply(wafer, function(x)inherits(x,"factor"))
# produces the following output:
maskdim visc.tem spinsp baketime aperture
T T T T T
exptime devtime etchtime pre.mean pre.dev
T T T F F
post.mean post.dev N
F F F
# second example:
formula(wafer, multiy = F)
#produces the following output:
pre.mean ~ maskdim + visc.tem + spinsp +
baketime + aperture + exptime + devtime +
etchtime + pre.mean