Constructs a matrix of terms representing a low order polynomial
and binds additional columns due to covariates ( the XMat matrix)
Usage
Krig.null.function(x, XMat = NULL, drop.XMat = FALSE, m)
Arguments
- x
Spatial locations
- XMat
Other covariates to be associated with each location.
- drop.XMat
If TRUE only the low order polynomial part is created.
- m
The polynomial order is (m-1).
Value
A matrix where the first columns are the polynomial terms and the
following columns are from XMat.
Details
This function can be modified to produce a different fixed part of the
spatial model. The arguments x, XMat and drop.XMat are required but other arguments
can be passed as part of a list in null.args in the call to Krig.