Hi Abani, I noted a slip in my last comment. For "more elliptical" read "less elliptical" regards Bill .
-----Original Message----- From: Abani R Samal [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 29, 2007 8:57 PM To: Bill Northrop Subject: Re: AI-GEOSTATS: Block model differences Hi Bill, My variogram ranges are "shorter" than the earlier correlogram models. I think in my case the variogram values increase at a higher rate than the older model. Isn't that right? If thas true then the samples near the block centers (within the range) should get higher weights than the samples farther from the block centers. Bill, please correct me if I am wrong. Abani ************************************************************ ----- Original Message ---- From: Bill Northrop <[EMAIL PROTECTED]> To: Abani R Samal <[EMAIL PROTECTED]> Sent: Tuesday, May 29, 2007 8:46:12 AM Subject: RE: AI-GEOSTATS: Block model differences Hi Abani, With regards to your "secondly statement", I would say that you are obtaining more measured estimates because your variogram values now increase at a lower rate with increasing lag, thus giving more weight to samples further away than in your previous model.If this is not the case then we must think again. Regards Bill Northrop -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Abani R Samal Sent: Thursday, May 24, 2007 7:42 PM To: [email protected] Subject: AI-GEOSTATS: Block model differences Dear List, I received a block model which used a correlogram model to krig. The ore-body strikes approx. N35E, dips approx. 35 degrees in NW direction. I modeled the variograms and found the followings: 1: My directions of anisotroy are along the inclined ore-body (the earlier correlograms were not along the ore body). 2: My ranges are shorter than the earlier correlogram ranges. earlier correlograms had two structures, which I don't see in my variograms. The likely reason for this is that the earlier person doing correlogram model did not keep its sill below a standard variance/ correlogram line. In my case I kept my variogram sills below the variance line (using ISATIS). 3: My search ellipsoid had same dimensions as earlier search ellipsoid, but my search ellipsoid oriented along the ore-body, where as the earlier one did not. 4: The measured and indicated resources are categorized based on distance (from block center to sample) and min.-max. number of samples used for interpolation of the block. I am getting approx. 30% of more resources in the measured category blocks. I am needing a valid explanation for this: I think, because of the re-orientation of my search ellipsoid (along the ore body), I am able to find more blocks meeting the minimum sample criteria for estimation (than the earlier model): Is this a valid reason? Secondly, also I think as my variograms are having shorter ranges, I am allowing more blocks to be estimated from nearest samples than the earlier model: Is this right? I'll highly appreciate your valuable comments/ suggestions. Regards, Abani R Samal ************************************************************ ABANI RANJAN SAMAL 11183 West 17th Avenue, APt 201 Lakewood, CO 80215 http://myprofile.cos.com/arsamal _____ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. <http://us.rd.yahoo.com/evt=48224/*http://sims.yahoo.com/> _____ Don't get soaked. Take a <http://tools.search.yahoo.com/shortcuts/?fr=oni_on_mail&#news> quick peak at the forecast with the Yahoo! <http://tools.search.yahoo.com/shortcuts/?fr=oni_on_mail&#news> Search weather shortcut.
