Fitting Kriging Models
km1Nugget.init is used to give good initial values to fit kriging models when there is an unknown nugget effect to be estimated.
an object of class
The procedure can be summarized in 4 stages :
|1)|| Compute the variogram and deduce a first estimation of the total variance. If an initial value is provided for
|2)|| Simulate several values for the nugget effect and the process variance, around the estimations obtained at stage 1). The number of simulations is the one given in
|3)|| If no initial value is provided for the other covariance parameters, simulate them uniformly inside the domain delimited by
a matrix whose rows contain initial vectors of parameters.
a vector containing the function values corresponding to
a list containing the covariance objects corresponding to
vectors containing lower and upper bounds for parameters.