Log-Likelihood function involved in Magma during the maximisation step of the training. The log-Likelihood is defined as a simple Gaussian likelihood added with correction trace term.
logL_GP_mod(hp, db, mean, kern, post_cov, pen_diag)
A number, corresponding to the value of the modified Gaussian log-Likelihood defined in Magma.
A tibble, data frame or named vector of hyper-parameters.
A tibble containing values we want to compute logL on. Required columns: Input, Output. Additional covariate columns are allowed.
A vector, specifying the mean of the GP at the reference inputs.
A kernel function.
A matrix, covariance parameter of the hyper-posterior. Used to compute the correction term.
A jitter term that is added to the covariance matrix to avoid numerical issues when inverting, in cases of nearly singular matrices.