Kriging::logMargPost
Description
Get the Maximized Log-Marginal Posterior Density of a Kriging
Model
Usage
Python
# k = Kriging(...) k.logMargPost()
R
# k = Kriging(...) k$logMargPost()
Matlab/Octave
% k = Kriging(...) k.logMargPost()
Details
Using the jointly robust prior
\(\pi_{\texttt{JR}}(\boldsymbol{\theta},\, \sigma^2, \,
\boldsymbol{\beta})\) the marginal or integrated posterior is the
function of \(\boldsymbol{\theta}\) obtained from the posterior density
by marginalizing out the GP variance \(\sigma^2\) and the vector
\(\boldsymbol{\beta}\) of trend coefficients. See
logMargPostFun.Kriging
for the
log-marginal posterior density. By maximizing this function
w.r.t. \(\boldsymbol{\theta}\) we get estimated correlation ranges which
are warranted to be postitive and finite \(0 < \theta_k < \infty\).
Value
The maximal value of the log-marginal posterior density, corresponding to the estimated value of the vector \(\boldsymbol{\theta}\) of correlation ranges.
Examples
f <- function(x) 1 - 1 / 2 * (sin(12 * x) / (1 + x) + 2 * cos(7 * x) * x^5 + 0.7)
set.seed(123)
X <- as.matrix(runif(10))
y <- f(X)
k <- Kriging(y, X, kernel = "matern3_2", objective="LMP")
print(k)
k$logMargPost()
Results
* data: 10x[0.0455565,0.940467] -> 10x[0.194057,1.00912]
* trend constant (est.): 0.388566
* variance (est.): 0.158896
* covariance:
* kernel: matern3_2
* range (est.): 0.313364
* fit:
* objective: LMP
* optim: BFGS
[1] 10.64938