geolm: Linear model for geostatistical data.
In gear: Geostatistical Analysis in R

Description Usage Arguments Details Value Author(s) Examples

geolm creates a geostatistical linear model object of the appropriate class based on the arguments, especially the cmod arguments.

geolm(
  formula,
  data,
  coordnames,
  mod,
  weights = NULL,
  mu = NULL,
  longlat = NULL,
  cmod = NULL
)

`formula`	An object of class `formula` providing a symbolic description of the model to be fitted. See Details of this function and `lm`.
`data`	A data frame containing the response, covariates, and location coordinates.
`coordnames`	The columns of `data` containing the spatial coordinates, provided as a formula (e.g., `~ x + y`), column numbers (e.g., `c(1, 2)`), or column names (e.g., `c("x", "y")`)
`mod`	A model object produced by one of the `cmod_*` functions, e.g., `cmod_std`.
`weights`	An optional vector of weights for the errors to be used in the fitting process. A vector that is proportional to the reciprocal variances of the errors, i.e., errors are assumed to be uncorrelated with variances `evar/weights`. Default is `NULL`, meaning that the weights are uniformly 1.
`mu`	A single numeric value indicating the consant mean of the spatial process if simple kriging is desired. Default is `NULL`, meaning that ordinary or universal kriging should be used.
`longlat`	A logical indicating whether Euclidean (`FALSE`) or Great Circle distance (WGS84 ellipsoid) (`longlat = TRUE`) should be used. Default is `FALSE`.
`cmod`	Retained for backwards compatibility. A model object produced by one of the `cmod_*` functions, e.g., `cmod_std`.

Note: for the multiresolution Gaussian process model, if cmod$est == "f" (i.e., if the nugget is finescale instead of measurement error), then the weights argument is internally set to rep(1, n), where n is the number of observations.

formula should be specified after the form y ~ x1 + x2, where y is the response variable and x1 and x2 are the covariates of interest. If mu is provided, the variables to the right of ~ are ignored.

Returns a geolm_* object, where * depends on mod.

Joshua French

data = data.frame(y = rnorm(10), x1 = runif(10),
                 x2 = runif(10))
d = geodist(data[,c("x1", "x2")])
mod = cmod_man(v = exp(-d), evar = 1)
gearmod = geolm(y ~ x1, data = data,
                coordnames = ~ x1 + x2, mod = mod)