Dear List, I am new to this field so please forgive me for my mistakes.
I am using gslib f77 free libraries for spatial interpolation of pollution data over a domain. I am using co-kriging for this purpose. I have calculated the semi variograms for the primary and secondary variable. It looks fine (even though in some cases variance decreases with distance) and I can fit them and get the values of nugget, sill and range for co-kriging. My query is with traditional cross semivariogam. Because of its negative values I am finding it difficult to fit it for use in the co-kriging. I read in some articles that variogram fitting models can not be used for the traditional cross semivariogam. I also read about the pseudo cross semivariogram, but there is no such option in the free gslib libraries to calculate pseudo cross semivariogram. (please correct me if I am wrong) I need help from the list. What should I do now to fit the traditional cross semivariogam having negative values and use the values of nugget, sill and range for co-kriging. thank you and regards -- Vikas Singh Department of Electronics for automation Faculty of Engineering University of Brescia Via Branze 38 - 25123 Brescia - ITALY ---------------------------------- Tel:+39 030 3715510 Fax:+39 030 380014 --------------------------------------------------------- http://www.ing.unibs.it/~vikas.singh ---------------------------------------------------------- + + 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/
