Computes fitting of the given empirical semivariogram while forcing the nugget value to 0 (this is invoked when the normal fitting causes a negative nugget value, which is mathematically pointless in Kriging estimation),
Computes fitting of the given empirical semivariogram using a ModelType's function definitions valueFunc() and jacobianFunc()
This creates an empirical variogram from the dataset, which is then used to fit into one of the semivariogram ModelType for use in Kriging Interpolation