On 8/12/19 8:21 PM, Emanuele Barca wrote: > Dear Edzer, > > maybe I found the solution. I found this in the predict function help: > "When a non-stationary (i.e., non-constant) mean is used, both for > simulation and prediction purposes the variogram model defined should be > that of the residual process, and not that of the raw observations" > Since my data were, actually, non-stationary, I applied the universal > co-kriging instead usual co-kriging. > now the maps of regression-kring and co-kriging are actually similar s > expected. > did I understand correctly the quoted sentence?
I think so, but hard to be sure given the information you provide. > > regards > > emanuele barca > ------------------------------ >> >> Message: 2 >> Date: Sat, 10 Aug 2019 10:41:38 +0200 >> From: Edzer Pebesma <[email protected]> >> To: [email protected] >> Subject: Re: [R-sig-Geo] regression-kriging and co-kriging >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset="utf-8" >> >> Hard to tell from your script. Maybe give a reproducible example? >> >> On 8/6/19 1:07 PM, Emanuele Barca wrote: >>> Dear r-sig-geo friends, >>> >>> I produced two maps garnered in the following way: >>> >>> # for regression-kriging >>> Piezo.map <-autoKrige(LivStat ~ Z, input_data = mydata.sp, new_data >>> = covariates, model = "Ste") >>> >>> Piezork.pred <- Piezo.map$krige_output$var1.pred >>> Piezork.coords <- Piezo.map$krige_output@coords >>> Piezork.out <- as.data.frame(cbind(Piezork.coords, Piezork.pred)) >>> colnames(Piezork.out)[1:2] <- c("X", "Y") >>> coordinates(Piezork.out) = ~ X + Y >>> gridded(Piezork.out) <- TRUE >>> >>> spplot(Piezork.out, main = list(label = "R-k Hydraulic head", cex = >>> 1.5)) >>> >>> #for co-kriging >>> g <- gstat(id = "Piezo", formula = LivStat ~ 1, data = mydata.sp, set >>> = list(nocheck = 1)) >>> g <- gstat(g, id = "Z", formula = Z ~ 1, data = mydata.sp, set = >>> list(nocheck = 1)) >>> >>> v.g <- variogram(g) >>> >>> #g <- gstat(g, id = "Piezo", model = vgm(150, "Mat", 1350, 0.0, kappa >>> = 1.9), fill.all = T)# >>> g <- gstat(g, id = "Piezo", model = vgm(0.7, "Ste", 1300, 18, kappa = >>> 1.9), fill.all = T)# >>> g.fit <- fit.lmc(v.g, g, fit.lmc = TRUE, correct.diagonal = 1.01) # >>> fit multivariable variogram model , fit.lmc = TRUE, correct.diagonal >>> = 1.01 >>> g.fit >>> plot(v.g, model = g.fit, main = "Fitted Variogram Models - Raw Data")# >>> #gridded(covariates) <- TRUE >>> g.cok <- predict(g.fit, newdata = covariates)#grid >>> >>> g.cok.pred <- g.cok@data$Piezo.pred >>> aaaa <- na.omit(g.cok.pred) >>> g.cok.coords <- g.cok@coords >>> g.cok.out <- as.data.frame(cbind(g.cok.coords, g.cok.pred)) >>> colnames(g.cok.out)[1:2] <- c("X", "Y") >>> coordinates(g.cok.out) = ~ X + Y >>> gridded(g.cok.out) <- TRUE >>> spplot(g.cok.out, main = list(label = "Hydraulic head with >>> Co-kriging", cex = 1.5)) >>> >>> ########################################################################################################################### >>> >>> >>> I am unable to understand why the first map appears as a raster and >>> the second not, notwithstanding the fact that they are both computed >>> on the same "covariates" DEM??? >>> >>> where is the mistake??? >>> >>> regards >>> >>> emanuele >>> >>> ________________________________________________________ >>> Emanuele Barca Researcher >>> Water Research Institute (IRSA-CNR) >>> Via De Blasio, 5 70123 Bari (Italy) >>> Phone +39 080 5820535 Fax +39 080 5313365 >>> Mobile +39 340 3420689 >>> _________________________________________________________ >>> >>> >>> >>> --- >>> Questa e-mail è stata controllata per individuare virus con Avast >>> antivirus. >>> https://www.avast.com/antivirus >>> >>> [[alternative HTML version deleted]] >>> >>> _______________________________________________ >>> R-sig-Geo mailing list >>> [email protected] >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >>> >> >> -- >> Edzer Pebesma >> Institute for Geoinformatics >> Heisenbergstrasse 2, 48151 Muenster, Germany >> Phone: +49 251 8333081 >> >> -------------- next part -------------- >> A non-text attachment was scrubbed... >> Name: pEpkey.asc >> Type: application/pgp-keys >> Size: 2472 bytes >> Desc: not available >> URL: >> <https://stat.ethz.ch/pipermail/r-sig-geo/attachments/20190810/b5cb9d77/attachment-0001.bin> >> >> >> >> ------------------------------ >> >> Subject: Digest Footer >> >> _______________________________________________ >> R-sig-Geo mailing list >> [email protected] >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >> >> >> ------------------------------ >> >> End of R-sig-Geo Digest, Vol 192, Issue 7 >> ***************************************** > > _______________________________________________ > R-sig-Geo mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics Heisenbergstrasse 2, 48151 Muenster, Germany Phone: +49 251 8333081
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