fac.design
fac.design
object, with factors, blocks and
center points as designated.
as.fac.design(x, factors = seq(length(x)), block = F, cpoints = F)
read.table
.
x
to use as factors. Can be
vector of column numbers or names.
"Quad"
, which
distinguishes design points from center points.
fac.design
.
The functions
fac.aov
and
plot.design
rely on the data having
attributes of the class
fac.design
. When the experiment is read from
an external file, a user can use
as.fac.design
to interface easily
to the fractional factorial functions of the S+DOX module.
If
cpoints
are designated, an extra, non-printing variable,
Quad,
is added to the returned
fac.design
. This factor is used by
formula.fac.design
to fit a quadratic term, testing center points
versus design points, in the model fit by
fac.aov
.
Avoid using factor names
F
and
T
as these can get confused with
FALSE
and
TRUE
. The default factor names skips these two letters.
raw.data <- read.table(file="myfile.txt",header=T) data.design <- as.fac.design(raw.data, 1:4)