The model matrices for each element of
formula(object),
calculated using
data, are bound together column-wise. When
multiple grouping levels are present (i.e. when `length(object) >
1'), the individual model matrices are combined from innermost (at
the leftmost position) to outermost (at the rightmost position).
USAGE:
model.matrix(object, data, contr)
REQUIRED ARGUMENTS:
object
an object inheriting from class
reStruct,
representing a random effects structure and consisting of a list of
pdMat objects.
data
a data frame in which to evaluate the variables defined in
formula(object).
OPTIONAL ARGUMENTS:
contr
an optional named list specifying the contrasts to be used
for representing the
factor variables in
data. The
components names should match the names of the variables in
data for which the contrasts are to be specified. The
components of this list will be used as the
contrasts
attribute of the corresponding factor. If missing, the default
contrast specification is used.
VALUE:
a matrix obtained by binding together, column-wise, the model matrices
for each element of
formula(object).
SEE ALSO:
,
,
,
EXAMPLES:
rs1 <- reStruct(list(Dog = ~day, Side = ~1), data = Pixel)
model.matrix(rs1, Pixel)