Fitting model parameters to spatial data (regionalised variables) and to linear (mixed) models
The function estimates arbitrary parameters of a random field specification with various methods. Currently, the models to be fitted can be
The fitting of max-stable random fields and others has not been implemented yet.
RFcrossvalidate(model, x, y=NULL, z=NULL, T=NULL, grid=NULL, data, params, lower=NULL, upper=NULL, method="ml", users.guess=NULL, distances=NULL, dim, optim.control=NULL, transform=NULL, full = FALSE, ...)
model,params |
object of class |
x |
vector of x coordinates, or object of class |
y,z |
optional vectors of y (z) coordinates, which should not be given if |
T |
optional vector of time coordinates, |
grid |
logical; the function finds itself the correct value in nearly all cases, so that usually |
data |
matrix, data.frame or object of class |
lower |
list or vector. Lower bounds for the parameters. If |
upper |
list or vector. Upper bounds for the parameters. See |
method |
Single method to be used for estimating, either
one of the |
users.guess |
User's guess of the parameters. All the parameters must be given using the same rules as for |
distances,dim |
another alternative for the argument |
optim.control |
control list for |
transform |
obsolete for users; use |
full |
logical.
If |
... |
for advanced use: further options and control arguments for the simulation that are passed to and processed by |
An object of the class
"RFcrossvalidate"
which is
a list with the following components, cf. xvalid
in the
package geoR :
data |
the original data. |
predicted |
the values predicted by cross-validation. |
krige.var |
the cross-validation prediction variance. |
error |
the differences |
std.error |
the errors divided by the square root of the prediction variances. |
p |
In contrast to geoR the p-value is returned, i.e. the probability that a difference with absolute value larger than the absolute value of the actual difference is observed. A method for If |
prints the summary
gives a summary
An important option is cross_refit
that determines
whether the model is refitted for each location left out.
Default is FALSE
. See also RFoptions
.
Martin Schlather, schlather@math.uni-mannheim.de, https://www.wim.uni-mannheim.de/schlather/
Ribeiro, P.J., Jr. and Diggle, P.J (2014) R package geoR.
Burnham, K. P. and Anderson, D. R. (2002) Model selection and Multi-Model Inference: A Practical Information-Theoretic Approach. 2nd edition. New York: Springer.
RFoptions(seed=0) ## *ANY* simulation will have the random seed 0; set ## RFoptions(seed=NA) to make them all random again ## currently disabled!
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