Arguments
space
a vector indicating the category spacing when fitting the polynomial model.
formula
a formula, as for other regression models.
times
a vector of times which occur within subject clusters.
poly
a numeric variable indicating the order of the polynomial contrasts used for the cut-point model.
data
a dataframe in which to interpret the variables occurring in the formula.
subjects
a character string specifying the name of the subject variable.
categories
a numeric variable indicating the number of ordinal score categories.