Fast Kriging and Geostatistics on Grids with Kronecker Covariance
Coerce grid values to numeric (double type)
Coerce grid values to integer
Coerce grid values to logical
convert to matrix
Convert grid data to vector of specified mode
Grid dimensions
Indices of grid points with missing data (NAs)
The number of grid-points
Math group generics
Calculate the mean value in a grid
Operations group generics
Heatmap plots
Auto-printing
Make a snapKrig grid list object
Check for presence of grid points with missing data (NAs)
Add bin labels to a variogram data frame
Set default parameter covariance parameter bounds for a Kronecker cova...
Compute kriging predictor (or variance) for an sk grid
Return coordinates of a grid of points in column-vectorized order
Stationary 1D correlation kernels
Construct 1D stationary correlation matrices for regularly spaced data
Convert "sk" grid to SpatRaster
Fit a covariance model to an sk grid by maximum likelihood
Generalized least squares (GLS) with Kronecker covariances for sk grid...
Return named vector of Kronecker covariance parameters initialized to ...
Likelihood of covariance model pars given the data in sk grid g
Make a sk grid object
Column-vectorization indices
Negative log-likelihood for parameter vector p
Initialize Kronecker covariance function parameters for a sk grid
Build a parameter list defining the 2d spatial Kronecker covariance mo...
Convert covariance parameter list to/from vectorized form
Plot grid data
Plot the covariance structure of a snapKrig model
Plot a semi-variogram
Up or down-scale a sk grid by an integer factor
Sub-grid point sampler for grid data
Sample point pair absolute differences for use in semi-variogram estim...
Random draw from multivariate normal distribution for sk grids
Snap a set of points to a "sk" grid
Return a sub-grid of a sk grid object
Find complete regular sub-grids in a sk grid object
Find column-vectorized index of a sub-grid
Extract Kronecker covariance parameters as plot-friendly strings
Efficiently compute yzx for symmetric Toeplitz matrices y and x
Check compatibility of entries in a sk grid object, and fill in any mi...
Generate a covariance matrix or its factorization
Multiply a vector by a power of the covariance matrix
Theoretical variogram function
Invert column-vectorization indices
Extract a sk list element (single-bracket access)
sk_methods.R Dean Koch, 2022 S3 methods for sk grid list objects
Single-bracket assign
Grid summary
Geostatistical modeling and kriging with gridded data using spatially separable covariance functions (Kronecker covariances). Kronecker products in these models provide shortcuts for solving large matrix problems in likelihood and conditional mean, making 'snapKrig' computationally efficient with large grids. The package supplies its own S3 grid object class, and a host of methods including plot, print, Ops, square bracket replace/assign, and more. Our computational methods are described in Koch, Lele, Lewis (2020) <doi:10.7939/r3-g6qb-bq70>.