Fitting variogram model with NLS in R

09 September 2013 1 8K Report

I tried to compare the result obtained by fitting the spherical variogram model using fit.variogram and nls functions. The large difference in the results is a great concern for me knowing that the two functions use Weighted Least Squares (WLS) approach for estimating parameters. The steps taken are as follows:

## Fit empirical semivariogram using gstat

empvar

Richard James Telford

fit.variogram is weighted by the number of observations in each distance class - see help file for details. That might explain the difference between the fit.variogram results and the nls results.

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