Hi, as usual I have a problem with R functions! I formulated a geostatistical model with geoR.
I decided to include some covariates in my model, and I estimated all the parameters (linear model and covariance function parameters) by the likfit function as follows: mod1<-likfit(geodata, ini=varfitmodel, trend=~cov1 +cov2, lambda=0.5, cov.model="matern",kappa=0.5) Once I obtained my best model, I'd like to validate it using an external dataset by using the function xvalid. First of all, I transformed the external dataset in a geodata object, as usual, named "validation_data" ,where also covariates were included. Then I tried the following syntax: Validation<-xvalid(geodata, model=mod1, locations.xvalid=validation_data$coords, data.xvalid= validation_data$data) Bur R says: Trend elements not found. My question is: how can I specify the trend structure within the xvalid function? Thank a lot [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.