Hi John, Not sure how to address your initial question but it looks like what you are doing is similar to preferential sampling. If so, you may want to look at the paper Geostatistical Inference under Preferential Sampling. The authors provide provide code and data at http://www.lancs.ac.uk/~diggle/
Hope this helps. Virgilio El lun, 19-10-2009 a las 08:47 -0500, Carson, John escribió: > Dear r-sig-geostat members, > > > > I have a spatial soil sampling design which will be used for a > moderately large number of areas. The first or primary stage is > systematic. Any primary locations observed to exceed one or more > thresholds (it's a multivariable problem) will trigger (composite) > sample collection in the 4 adjacent grid areas. So the sampling is > adaptive cluster sampling, and I use sampling weights for > Horvitz-Thompson estimation (prop to 1/(prob of selection)). I know > that variograms estimated with this kind of clustered data can be > biased. I would like to directly incorporate sampling weights into the > variogram estimation. I have used gstat and geoR previously and don't > see an easy way to use external weights. > > > > Does anyone know how to use external weights for variogram estimation in > these packages? Or are there other libraries that would work better? > > > > Thanks in advance, > > John > > > > John H. Carson Jr., PhD > > Senior Statistician > > Applied Sciences & Engineering > > Shaw Environmental & Infrastructure > > 16406 US Rte 224 East > > Findlay, OH 45840 > > Phone 419-425-6156 > > Fax 419-425-6085 > > john.car...@shawgrp.com > > > > http://www.shawgrp.com/ <http://www.shawgrp.com/> > > Shaw(tm) a world of Solutions(tm) <http://www.shawgrp.com/> > > > > To call in the statistician after the experiment is done may be no more > than asking him to perform a post-mortem examination: he may be able to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The combination of some data and an aching desire for an answer does not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > > > > > ****Internet Email Confidentiality Footer**** > Privileged/Confidential Information may be contained in this > message. If you are not the addressee indicated in this message (or > responsible for delivery of the message to such person), you may > not copy or deliver this message to anyone. In such case, you > should destroy this message and notify the sender by reply email. > Please advise immediately if you or your employer do not consent to > Internet email for messages of this kind. Opinions, conclusions and > other information in this message that do not relate to the > official business of The Shaw Group Inc. or its subsidiaries shall > be understood as neither given nor endorsed by it. > ______________________________________ The Shaw Group Inc. > http://www.shawgrp.com > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
