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Hi, R-folks:<BR> <BR>I have been tryin many combination of parameter to make Matern variogram to work, but I can't find the available one. I'm near to be crazy.<BR>I tiped:<BR>Año2003Selg.lf<-likfit(Año2003Selg,cov.model="matern",ini.cov.pars=c(1.5,14),kappa=2.5,fix.kappa=FALSE,nugget=0.08,lambda=0.008,fix.lambda=FALSE,hessian=TRUE)<BR> <BR>the hessian shows:<BR> <BR><FONT color=#ff0000>$hessian<BR> [,1] [,2] [,3] [,4]<BR>[1,] 9.139986 -8.562736e+00 41.648355 -3.801615<BR>[2,] -8.562736 3.351952e+159 -147.279881 -7.083089<BR>[3,] 41.648355 -1.472799e+02 347.493191 -7.509035<BR>[4,] -3.801615 -7.083089e+00 -7.509035 90.681917<BR></FONT><BR>Then, I put: solve(Año2003Selg.lf$info.minimisation.function$hessian)<BR> <BR>...and it's shown as following:<BR> <BR><FONT color=#ff0000>Error in solve.default(Año2003Selg.lf$info.minimisation.function$hessian) : <BR> sistem is computationally singular: number of reciprocity condition= 1.05091e-159</FONT><BR><BR>on account of I work in Spanish, it's shown:<BR><FONT color=#ff0000>Error in solve.default(Año2003Selg.lf$info.minimisation.function$hessian) : <BR> sistema es computacionalmente singular: número de condición recíproco = 1.05091e-159</FONT><BR><FONT color=#ff0000></FONT> <BR><FONT color=#000000>I also wander if there is any limit for kappa. Which one would be the maximun. As far as I'm concerned, it must be always major than cero, right?. I also know that its values depend on the tendency of cloud semivariogram, if it flattens slowly (Gaussian) it's major.</FONT><BR> <BR>I'd thank the one available to answer my desperate question.<BR><BR> </body>
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