gr_GP_mod: Gradient of the modified logLikelihood for GPs in Magma
Description
Gradient of the modified logLikelihood for GPs in Magma
Usage
gr_GP_mod(hp, db, mean, kern, post_cov, pen_diag)
Value
A named vector, corresponding to the value of the hyper-parameters
gradients for the modified Gaussian log-Likelihood involved in Magma.
Arguments
- hp
A tibble, data frame or named vector containing hyper-parameters.
- db
A tibble containing the values we want to compute the logL on.
Required columns: Input, Output. Additional covariate columns are allowed.
- mean
A vector, specifying the mean of the GPs at the reference inputs.
- kern
A kernel function.
- post_cov
A matrix, covariance parameter of the hyper-posterior.
Used to compute the correction term.
- pen_diag
A jitter term that is added to the covariance matrix to avoid
numerical issues when inverting, in cases of nearly singular matrices.