Thanks for the info. I don't mind you plugging your book, that was one of the questions I asked : What is a good reference on this subject.
See this is where I start getting confused with terminology. I'm talking about KED (Kriging with External Drift) and then you start talking about Universal Kriging. If I understand correctly they are not the same thing? With Universal Kriging you remove the trend and Krig the residuals but in KED you use the trend(drift) in the actual krig matrix? Mike -----Original Message----- From: Isobel Clark [mailto:[EMAIL PROTECTED]] Sent: Thursday, December 06, 2001 11:18 AM To: Michael Dennis Cc: [EMAIL PROTECTED] Subject: RE: AI-GEOSTATS: Kriging with External Drift > I'll see if I can get a > copy of the book you mention to look at to see if it > helps me out. > > You say that KED uses a shape function for the > "Drift" data. 'shape functions' can be anything you like but most people stick to simple polynomials. To use Univeral Kriging the only constraint is that it has to be expressed as a linear function in the coefficients. That is: b0 + b1 * some function + b2 * some other function and so on, where the b's are the coefficients. All this is explained in detail in Chapter 12 of Practical Geostatistics 2000, but we aren't allowed to say that on the open list ;-) You can try it out free (completely) with the kriging game in my briefcase. This shows you the equations and the terms calculated. A full tutorial on Universal Kriging is also available in the briefcase and can be run with the free PG2000 software. Find them all at: http://uk.geocities.com/drisobelclark/briefcase.html Let us know if we can be of further help. Isobel Clark ________________________________________________________________ Nokia 5510 looks weird sounds great. Go to http://uk.promotions.yahoo.com/nokia/ discover and win it! The competition ends 16 th of December 2001. -- * To post a message to the list, send it to [EMAIL PROTECTED] * As a general service to the users, please remember to post a summary of any useful responses to your questions. * To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list * Support to the list is provided at http://www.ai-geostats.org
