designfactors-class: Class designfactors
In planor: Generation of Regular Factorial Designs

Description Objects from the Class Slots Methods Details Author(s) See Also Examples

An S4 class to represent the design factors and store their characteristics.

Objects from this class can be created explicitly by calls to planor.factors or implicitly by functions such as planor.designkey.

fact.info: a dataframe with one row per factor and with columns progressively storing information on the factors, in particular their numbers of levels (nlev).
pseudo.info: a dataframe with one row per pseudofactor and with columns progressively storing information on the pseudofactors.
levels: a list of numeric or character vectors, with each vector containing the levels of one factor.

[: extract a subset of factors and update all the slots.
bind: bind two objects. See bind method.
length: return the number of factors.
names: return the names of the factors.

Depending on the context and on the construction stage, fact.info may contain logical columns that identify the block factors (block), the ordered factors (ordered), the basic factors (basic) and so on. It may also include columns that store the information on the hierarchy relationships between factors, if any.

In package planor, factors are systematically decomposed into pseudofactors which all have a prime number of levels and which play a key role in the design generation. The information on the pseudofactors is stored in the pseudo.info slot. In addition to the columns of fact.info, it contains a column (called parent) to give the factor that each pseudofactor decomposes.

Monod, H. and Bouvier, A.

Creator function: planor.factors

F1 <- planor.factors(factors=c("block",LETTERS[1:4]), nlevels=c(6,6,4,2,6))
F2 <- planor.factors(factors=c("block",LETTERS[11:12]), nlevels=c(4,6,6))
### Method bind - a warning will be issued because two factors
### in F1 and F2 have the same name
F3 <- bind(F1,F2) 
names(F3)
length(F3)
F3@levels
F3.trt <- F3[c(2:5,7,8)]
names(F3.trt)