Hello, You need to provide more information on your problem. For example, how many threshold values did you use for indicator kriging and did you observe large differences between indicator variogram models (e.g. anisotropy) for different thresholds. I am also assuming you are using the mean of the probability distribution obtained by IK (i.e. E-type estimate). Last how did you interpolate and extrapolate the upper and lower tails of your discrete distributions. Nevertheless I am not surprised by your findings. As long as you are using the same data in these least square interpolation techniques, you will get similar results.
Regards, Pierre Goovaerts <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> Dr. Pierre Goovaerts Consultant in (Geo)statistics President of PGeostat, LLC and Senior Chief Scientist with Biomedware Inc. 710 Ridgemont Lane Ann Arbor, Michigan, 48103-1535, U.S.A. E-mail: [EMAIL PROTECTED] Phone: (734) 668-9900 Fax: (734) 668-7788 http://alumni.engin.umich.edu/~goovaert/ <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> On Sun, 12 Jan 2003, [iso-8859-1] Elmidio Est�vez Cruz wrote: > Dear All: > > I�m working with a Au gossan deposit. The data come from grade control of 8 benches >in the mine. All the histograms show evidences of bimodality .The presence of a >complex population is geologically explained by the fact that gold is hosted by >different lithological units (limonite, sandstone, clay etc.), which are mixed and it >is not possible to separate at present mining scale (5m benches). The variograms of >Au show a clear spatial structure with a range of around 30m in all benches. Based on >this spatial correlation some people have proposed to used OK to estimate the Au >grade in 5x5m block on the other hand the mixture of population indicates the >violation of stationarity (homogeneity) indispensable for the application of OK. >According to literature the only method that mitigate this problems is IK. I have >interpolated the grade using IK but I found a high correlation between OK and IK >estimates. I also crossvalidated the methods and found similar errors. What could be >the reason for that? Is there any method to demonstrate which interpolation >techniques works better in this situation? > > Best regards, > > MSc. Emidio Est�vez Cruz > > Dpto de Geolog�a > > Universidad de Pinar del R�o > > -- * 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
