Javier > Is it supposed the sill is always the variance of > the set of data? The sill of the calculated semi-variogram is an estimate of the true variance of the data (if stationary) which is based on the assumption that values are inter-related according to the distance (and possibly direction) between them.
The standard statistical variance is an estimate of the true variance of the data based on the assumption of random independent sampling from some stationary population. Two different estimates, on two different bases for the same quantity. One should lie within the confidence interval for the other with whatever percent confidence. Most statistical tests would suggest that one could be twice as high as the other before you need to worry about significant differences. Isobel Clark http://geoecosse.bizland.com/pg2000.htm __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- * 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
