hi, I have a problem with the functions variofit ant likfit. I have to chose the more appropriate variogram model for my specific problem and data. I write the alghoritm has follows: library(geoR) data(wolfcamp) v.e<-variog(wolfcamp) exp.vario<-variofit(v.e,ini.cov.pars=c(175226.94,139.81),cov.model="exponential",nugget=21903.37) lines(exp.vario,col=1) sph.vario<-variofit(v.e,ini.cov.pars=c(175226.94,139.81),cov.model="spherical",nugget=21903.37) lines(sph.vario,col=2) ..... exp.lik<-likfit(wolfcamp,coords=wolfcamp$coords,data=wolfcamp$data,ini.cov.pars=c(175226.94,139.81),cov.model="exponential",trend="cte",fix.kappa=FALSE,nugget=21903,37) lines(exp.lik,col=5) sph.lik<-likfit(wolfcamp,coords=wolfcamp$coords,data=wolfcamp$data,ini.cov.pars=c(175226.94,139.81),cov.model="spherical",trend="cte",fix.kappa=FALSE,nugget=21903,37) lines(sph.lik,col=6) .... the lines of the resultant variograms are different using variofit or likfit, but when I change the cov.model (from exp to sph or lin....) the program gives identical result. I think this is incorrect.... can you tell me if I made any mistake in the implementations of the algorithm. thank you. P.S. sorry for my english. katia -- View this message in context: http://r.789695.n4.nabble.com/geoR-variofit-likfit-tp4013734p4013734.html Sent from the R help mailing list archive at Nabble.com.