To predict sign-adjusted quantile indices of a test set.
# S3 method for Qindex
predict(object, newdata = object@gam$data, ...)Function predict.Qindex returns a double
vector, which is the predicted sign-adjusted quantile indices on the test set.
an Qindex object based on the training set.
test data.frame, with at least
the response \(y^{\text{new}}\) and
the double matrix of
functional predictor values \(X^{\text{new}}\)
of the test set, tabulated on the same \(x\)-grid as the training set \(X\).
If missing, the training set object@gam$data will be used.
additional parameters, currently not in use.
Function predict.Qindex computes
the predicted sign-adjusted quantile indices on the test set,
which is
the product of function predict.gam return
and the correlation sign based on training set
(object@sign, see Step 3 of section Details of function Qindex).
Multiplication by object@sign is required to ensure
that the predicted sign-adjusted quantile indices
are positively associated with the training functional predictor values
at the selected tabulating grid.