I have reviewed all the scripts that appear http://cran.es.r-project.org/ and I cann?t find any suitable for cross-validation with a model of the form y aX^(b). exp(cZ). Please can someone help me? Thanks, a lot of!! -- View this message in context: http://www.nabble.com/cross-validation-tp22674165p22674165.html Sent from the R help mailing list archive at Nabble.com.