Covariance functions of GRFs
Calculate values of the covariance function with geoR::cov.spatial()
:
sigma2 <- 1
phi <- 0.2
tibble::tibble(
distance = seq(0, 1, 0.2),
covariance_1 = cov.spatial(
distance,
cov.pars = c(sigma2, phi),
cov.model = "matern",
kappa = 0.5 # default
),
covariance_2 = cov.spatial(
distance,
cov.pars = c(sigma2, phi),
cov.model = "matern",
kappa = 10
)
)
## # A tibble: 6 × 3
## distance covariance_1 covariance_2
## <dbl> <dbl> <dbl>
## 1 0 1 1
## 2 0.2 0.368 0.973
## 3 0.4 0.135 0.896
## 4 0.6 0.0498 0.782
## 5 0.8 0.0183 0.649
## 6 1 0.00674 0.513