I am unsure how to specify a power or linear variogram model in gstat; could someone please provide me an example. Thanks, ************************************************** William C. Thayer, P.E. Environmental Science Center Syracuse Research Corporation 6225 Running Ridge Road North Syracuse, NY 13212-2510 phone: (315) 452-8424 fax: (315) 452-8090 email: [EMAIL PROTECTED] web: http://esc.syrres.com/ **************************************************