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8 fit.variogram.reml Arguments formula formula defining the response vector and (possible) regressors; in case of absence of regressors, use e.g. z~1 locations spatial data locations; a formula with the coordinate variables in the right hand (dependent variable) side. data data frame where the names in formula and locations are to be found model variogram model to be fitted, output of vgm debug.level debug level; set to 65 to see the iteration trace and log likelihood set additional options that can be set; use set=list(iter=100) to set the max. number of iterations to 100. degree order of trend surface in the location, between 0 and 3 Value an object of class "variogramModel"; see fit.variogram Note This implementation only uses REML fitting of sill parameters. For each iteration, an n×n matrix is inverted, with $n$ the number of observations, so for large data sets this method becomes demanding. I guess there is much more to likelihood variogram fitting in package geoR, and probably also in nlme. Author(s) Edzer Pebesma References Christensen, R. Linear models for multivariate, Time Series, and Spatial Data, Springer, NY, 1991. Kitanidis, P., Minimum-Variance Quadratic Estimation of Covariances of Regionalized Variables, Mathematical Geology 17 (2), 195–208, 1985 See Also fit.variogram, Examples data(meuse) fit.variogram.reml(log(zinc)~1, ~x+y, meuse, model = vgm(1, "Sph", 900,1))