Predicted values are obtained at the specified values of
primary for each object. If either object1 or
object2 have a grouping structure
(i.e. getGroups(object) is not NULL), predicted values
are obtained for each group. When both objects determine groups, the
group levels must be the same. If other covariates besides
primary are used in the prediction model, their group-wise averages
(numeric covariates) or most frequent values (categorical covariates)
are used to obtain the predicted values. The original observations are
also included in the returned object.
a data frame with four columns representing, respectively, the values
of the primary covariate, the groups (if object does not have a
grouping structure, all elements will be 1), the predicted or
observed values, and the type of value in the third column: the
objects' names are used to classify the predicted values and
original is used for the observed values. The returned object
inherits from classes comparePred and augPred.