Dear all, I have built glm models based on presences/absences and a number of predictor maps and would like to compute habitat suitability based on the modelled coefficients.
I thought this is pretty straight forward and wanted to use predict() and supply the new data in a data frame, with one column for each predictor. However, I do get an error msg warning me that the number of rows for old and new data do not match. the script looks like that: model<-glm(species~temp+prec+elev,family=binomial(link=logit)) #whereby temp,prec,elev are in vector format and contain the elements on species presence/absence; species is vector of 0's and 1's (length=319) wholearea<-data.frame(cbind(as.vector(temperature),as.vector (precipitation),as.vector(elevation)) # (length=7526) predict(model, newdata=wholearea,type="response") Warning message: 'newdata' had 7526 rows but variable(s) found have 319 rows. Ive searched quite a while for the answer now, has anyone encountered that problem before?? thanx in advance. Katrin Fleischer MSc Student Computational Geo-ecology University of Amsterdam ______________________________________________ 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.