Gregoire, I do not have the book with me right now, but what (you and) I do know is that
ln(x)=ln(10)*log10(x) The difference is only a multiplication by a constant, so it cannot be true that one case does involve the Lagrange multiplier and the other does not. Gerard Gerard B.M. Heuvelink Wageningen University and Research Centre P.O. Box 47 6700 AA Wageningen The Netherlands tel +31 317 474628 / 482420 email [EMAIL PROTECTED] -----Original Message----- From: Gregoire Dubois [mailto:[EMAIL PROTECTED] Sent: maandag 28 juli 2003 11:39 To: [EMAIL PROTECTED] Subject: AI-GEOSTATS: Log-normal back transform in Webster & Oliver In the book "Geostatistics for Environmental Scientists" By Richard Webster & Margaret A. Oliver, Wiley (2000), one will find in page 180 a brief discussion on the back-transformation of the kriging estimates. In ordinary kriging, when the natural logarithm (ln) is used, the back-transformation will involve the Lagrange parameter (see equation 8.36). No problem so far. But... the authors write in equation 8.38 that if one is using common logarithms (log10) instead, the unbiased back-transformation of the ordinary kriging estimates does not involve the Lagrange multiplier anymore. Is this correct ? In the affirmative, can someone point me to a paper discussing "natural" log normal kriging versus "common" log normal kriging ? Thanks again for any help. Regards, Gregoire -- * 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 -- * 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
