This function is used by mds.ct to fit a symmetric version of
the sandwich smoother of Xiao et al. (2013).
Usage
s3(Y, B, P, lambda = exp(-10:20))
Value
A list with components
gcv
generalized cross-validation (GCV) criterion for each value of lambda
bestlam
value of lambda minimizing the GCV
coefmat
matrix of tensor product B-spline coefficients
Yhat
the smoothed version of Y
Arguments
Y
a square symmetric matrix
B
a B-spline basis evaluation matrix
P
a penalty matrix
lambda
a vector of smoothing parameter values
Author
Philip Tzvi Reiss <reiss@stat.haifa.ac.il>
References
Xiao, L., Li, Y. & Ruppert, D. (2013). Fast bivariate P-splines: the sandwich smoother.
Journal of the Royal Statistical Society Series B, 75(3), 577–599.