AI-GEOSTATS: Variogram sill
Hello, I was wondering about some variogram models not having a sill. Does this mean that semi-variogram values can be greater than the population variance, in which case you would have negative covariances, or is the population variance the maximum these models, e.g. linear model, may reach. + + 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/
AI-GEOSTATS: Variogram sill
Hello, I was wondering about some variogram models not having a sill. Does this mean that semi-variogram values can be greater than the population variance, in which case you would have negative covariances, or is the population variance the maximum these models, e.g. linear model, may reach. + + 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/
AI-GEOSTATS: Re: standardized anomaly
Sebastiano You will be fine so long as you actually have a "stationary" phenomenon. That is, there is a constant mean and standard deviation over your study area -- no trends, no discontinuities, no changes of behaviour. Such a transformation also assumes that your data follow a fairly symmetrical histogram. Your semi-variogram will look exaclty the same as your 'raw' data semi-variogram but should have a sill around 1. Isobel http://www.kriging.comSebastiano Trevisani <[EMAIL PROTECTED]> wrote: Dear list memberA procedural question for you...I'm thinking to transform my data in a standardized anomaly [i.e. (raw datum- sample average)/sample standard deviation)] and then I`ll perfom the geostatistical analysis on these transformed data. At first glance, I don't see problem in the back-transformation of interpolated data and in the correct evaluation of estimation variance. Am I wrong?SincerelySebastiano++ 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/
AI-GEOSTATS: standardized anomaly
Dear list member A procedural question for you... I'm thinking to transform my data in a standardized anomaly [i.e. (raw datum- sample average)/sample standard deviation)] and then I`ll perfom the geostatistical analysis on these transformed data. At first glance, I don't see problem in the back-transformation of interpolated data and in the correct evaluation of estimation variance. Am I wrong? Sincerely Sebastiano + + 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/
