Re: AI-GEOSTATS: Kriging variance

[Marache Antoine]

[EMAIL PROTECTED] a écrit : Hi, Are your variables sampled on the same locations? Are your variables A and B correlated? We have two cases. In the first one A and B are not sampled at the same location ; my problem is for this case. In the second case, A and B are sampled at the same location, but in this case I have calculated A*B at sampled location and kriged the variable C=A*B. Can you calculate the product A*B at sampled locations and perform variogram analysis and krige the product? In the second case described above, yes; in the first case, no. You suggest to use the definition of the variance. What would you use for AB? I don't understand what you mean. Best regards. Best regards, Steinar Ellefmo Post doc research fellow Dep. of Geology and Minerals Resources Engineering, Norwegian University of Science and Technology, NTNU Sitat Marache Antoine <[EMAIL PROTECTED]>: Dear list, I have two maps of two variables (A and B) obtained by kriging independantly one to the other. I am interested by the map of the C variable which is the multiplication of A*B. I can so obtained the map of C by calculating the product A*B at each node of the grid. How can I obtained the kriging variance map of the C variable? Do you think I can use the definition of the variance(A*B) = E((AB)²)-(E(AB))² by replacing E(AB) by the estimation of AB obtained from the two initials maps for each grid node ? If it isn't true, what solution can I use? Thanks for your help, sincerely yours, Antoine Marache. -- Antoine MARACHE Maître de Conférences GHYMAC (CDGA) - Université Bordeaux 1 Av. des Facultés 33405 - Talence Cedex FRANCE Tél : +33 (0)5 40 00 88 27 Fax : +33 (0)5 40 00 31 13 Mél : [EMAIL PROTECTED] + + To post a message to the list, send it to ai-geostats@jrc.it + 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/ -- Antoine MARACHE Maître de Conférences GHYMAC (CDGA) - Université Bordeaux 1 Av. des Facultés 33405 - Talence Cedex FRANCE Tél : +33 (0)5 40 00 88 27 Fax : +33 (0)5 40 00 31 13 Mél : [EMAIL PROTECTED] + + To post a message to the list, send it to ai-geostats@jrc.it + 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/