Calculate the second derivative of the likelihood function with respect to
one of the hyperparameters, given the first and second derivative of the
kernel with respect to that hyperparameter.
Usage
D2(d1, d2, inv.Q, Alpha.Q)
Value
A number.
Arguments
d1
First derivative of the kernel function with respect to the required
hyperparameter.
d2
Second derivative of the kernel function with respect to the
required hyperparameter.
inv.Q
Inverse of covariance matrix Q.
Alpha.Q
This is alpha * alpha'- invQ, where invQ is the inverse of the
covariance matrix Q, and alpha = invQ * Y, where Y is the response.
Details
The function calculates the second derivative of the log-likelihood,
using the first and second derivative of the kernel functions.
References
Shi, J. Q., and Choi, T. (2011), ``Gaussian Process Regression
Analysis for Functional Data'', CRC Press.