FIC_reorder_univar      Univariate ordering under FIC approximation,
                        first m chosen by m iter of dense univariate
                        reordering
VeccTMVN                VeccTMVN
Vecc_reorder            Univariate ordering under Vecchia approximation
find_nn_corr            Find ordered nearest neighbors based on a
                        correlation Matrix. Assuming the absolute value
                        of the correlation is monotonically decreasing
                        with distance. Returns an n X (m + 1) matrix
                        similar to 'GpGp::find_ordered_nn'.
get_sp_inv_chol         Get the inverse upper Cholesky factor under the
                        Vecchia approximation
loglk_censor_MVN        Compute censored multivariate normal (MVN)
                        log-probabilities that have spatial covariance
                        matrices using Vecchia approximation
mvrandn                 Simulate truncated multivariate normal (TMVN)
                        using the Vecchia approximation
mvrandt                 Simulate truncated multivariate normal (TMVT)
                        using the Vecchia approximation
pmvn                    Compute multivariate normal (MVN) probabilities
                        that have spatial covariance matrices using
                        Vecchia approximation
pmvn_MLMC               Applying the multi-level Monte Carlo (MLMC)
                        technique to the pmvn function The function
                        uses 'NLevel1 = 1' for 'm = m2' and the same
                        exponential tilting parameter as 'm = m1' to
                        compute one MC estimate. This MC estimate is
                        used to correct the bias from the Vecchia
                        approximation
pmvt                    Compute multivariate Student-t (MVT)
                        probabilities that have spatial covariance
                        matrices using Vecchia approximation
pmvt_MLMC               Applying the multi-level Monte Carlo (MLMC)
                        technique to the pmvt function The function
                        uses 'NLevel1 = 1' for 'm = m2' and the same
                        exponential tilting parameter as 'm = m1' to
                        compute one MC estimate. This MC estimate is
                        used to correct the bias from the Vecchia
                        approximation
ptmvrandn               Simulate partially censored multivariate normal
                        (MVN) at censored locations using the Vecchia
                        approximation
univar_order            Univariate variable reordering, described in
                        Genz and Bretz (2009) If failed due to PD
                        singularity, the unfinished order will be
                        returned and a warning will be issued
