Create a spatial covariance parameter object for use with other functions.
Arguments
- spcov_type
The spatial covariance function type. Available options include
"exponential"
,"spherical"
,"gaussian"
,"triangular"
,"circular"
,"cubic"
,"pentaspherical"
,"cosine"
,"wave"
,"jbessel"
,"gravity"
,"rquad"
,"magnetic"
,"matern"
,"cauchy"
,"pexponential"
,"car"
,"sar"
, and"none"
.- de
The spatially dependent (correlated) random error variance. Commonly referred to as a partial sill.
- ie
The spatially independent (uncorrelated) random error variance. Commonly referred to as a nugget.
- range
The correlation parameter.
- extra
An extra covariance parameter used when
spcov_type
is"matern"
,"cauchy"
,"pexponential"
,"car"
, or"sar"
.- rotate
Anisotropy rotation parameter (from 0 to \(\pi\) radians). A value of 0 (the default) implies no rotation. Not used if
spcov_type
is"car"
or"sar"
.- scale
Anisotropy scale parameter (from 0 to 1). A value of 1 (the default) implies no scaling. Not used if
spcov_type
is"car"
or"sar"
.
Details
Generally, all arguments to spcov_params
must be specified, though
default arguments are often chosen based on spcov_type
.
When spcov_type
is car
or
sar
, ie
is assumed to be 0 unless specified otherwise.
For full parameterizations of all spatial covariance
functions, see spcov_initial()
.