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