Hi Digby, Some consideration in the definition of 'population variance' might be useful. The semi-variogram is (typically) attempting to model the underlying process generating the regionalized variable, so the sill should be thought of as the 'variance of the _process_' rather than the 'variance of the regionalized variable within the survey extent'.
If you were interested in the 'population variance of the survey extent', then this would be better approximated by estimating the double integral of the semi-variogram model. (Estimating that doesn't require a sill within the model .. just computer grunt :-) Mat > Hello, > > I was wondering about some variogram models not having a > sill. > Does this mean that semi-variogram values can be greater > than > the population variance, in which case you would have > negative > covariances, or is the population variance the maximum these > models, e.g. linear model, may reach. > + > + To post a message to the list, send it to [email protected] > + To unsubscribe, send email to majordomo@ jrc.it with no subject and > "unsubscribe ai-geostats" in the message body. DO NOT SEND > Subscribe/Unsubscribe requests to the list + As a general service to list > users, please remember to post a summary of any useful responses to your > questions. + Support to the forum can be found at > http://www.ai-geostats.org/ -- ------------------------------------------------- Prof. Dr. K. Gerald v.d. Boogaart Professor als Juniorprofessor fuer Statistik http://www.math-inf.uni-greifswald.de/statistik/ Bro: Franz-Mehring-Str. 48, 1.Etage rechts e-mail: [EMAIL PROTECTED] phone: 00+49 (0)3834/86-4621 fax: 00+49 (0)3834/86-4615 (Institut) paper-mail: Ernst-Moritz-Arndt-Universitaet Greifswald Institut fr Mathematik und Informatik Jahnstr. 15a 17487 Greifswald Germany -------------------------------------------------- + + To post a message to the list, send it to [email protected] + To unsubscribe, send email to majordomo@ jrc.it with no subject and "unsubscribe ai-geostats" in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/ + + To post a message to the list, send it to [email protected] + To unsubscribe, send email to majordomo@ jrc.it with no subject and "unsubscribe ai-geostats" in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/
