| calcQF | Calculate the Gaussian quadratic form for the NNGP approximation | 
| calculateAD_ns | Calculate A and D matrices for the NNGP approximation | 
| calculateU_ns | Calculate the (sparse) matrix U | 
| conditionLatentObs | Assign conditioning sets for the SGV approximation | 
| determineNeighbors | Determine the k-nearest neighbors for each spatial coordinate. | 
| dmnorm_nngp | Function for the evaluating the NNGP approximate density. | 
| dmnorm_sgv | Function for the evaluating the SGV approximate density. | 
| inverseEigen | Calculate covariance elements based on eigendecomposition components | 
| matern_corr | Calculate a stationary Matern correlation matrix | 
| nimble_sparse_chol | nimble_sparse_chol | 
| nimble_sparse_crossprod | nimble_sparse_crossprod | 
| nimble_sparse_solve | nimble_sparse_solve | 
| nimble_sparse_tcrossprod | nimble_sparse_tcrossprod | 
| nsCorr | Calculate a nonstationary Matern correlation matrix | 
| nsCrosscorr | Calculate a nonstationary Matern cross-correlation matrix | 
| nsCrossdist | Calculate coordinate-specific cross-distance matrices | 
| nsCrossdist3d | Calculate coordinate-specific cross-distance matrices, only for nearest neighbors and store in an array | 
| nsDist | Calculate coordinate-specific distance matrices | 
| nsDist3d | Calculate coordinate-specific distance matrices, only for nearest neighbors and store in an array | 
| nsgpModel | NIMBLE code for a generic nonstationary GP model | 
| nsgpPredict | Posterior prediction for the NSGP | 
| orderCoordinatesMMD | Order coordinates according to a maximum-minimum distance criterion. | 
| rmnorm_nngp | Function for the evaluating the NNGP approximate density. | 
| rmnorm_sgv | Function for the evaluating the SGV approximate density. | 
| R_sparse_chol | R_sparse_chol | 
| R_sparse_crossprod | nimble_sparse_crossprod | 
| R_sparse_solve | nimble_sparse_solve | 
| R_sparse_tcrossprod | nimble_sparse_tcrossprod | 
| sgvSetup | One-time setup wrapper function for the SGV approximation |