fit.lmc {gstat} | R Documentation |
Fit a Linear Model of Coregionalization to a Multivariable Sample Variogram; in case of a single variogram model (i.e., no nugget) this is equivalent to Intrinsic Correlation
fit.lmc(v, g, model, fit.ranges = FALSE, fit.lmc = !fit.ranges, ...)
v |
multivariable sample variogram, output of variogram |
g |
gstat object, output of gstat |
model |
variogram model, output of vgm; if supplied this value is used as initial value for each fit |
fit.ranges |
logical; determines whether the range coefficients (excluding that of the nugget component) should be fitted; or logical vector: determines for each range parameter of the variogram model whether it should be fitted or fixed. |
fit.lmc |
logical; if TRUE, each coefficient matrices of partial sills is guaranteed to be positive definite |
... |
parameters that get passed to fit.variogram |
returns an object of class gstat
, with fitted variograms;
This function does not use the iterative procedure proposed by M. Goulard and M. Voltz (Math. Geol., 24(3): 269-286; reproduced in Goovaerts' 1997 book) but uses simply two steps: first, each variogram model is fitted to a direct or cross variogram; next each of the partial sill coefficient matrices is approached by its in least squares sense closest positive definite matrices (by setting any negative eigenvalues to zero).
Edzer J. Pebesma
variogram, vgm, fit.variogram,
demo(cokriging)