Hi all I'm dealing with a supervised binary classification issue. I'd like to use the GBM package to classify individuals as uninfected/infected. I have 15 times more uninfected than infected individuals.
I was wondering if GBM models suffer in the case of imbalanced class sizes? I didn't find any references answering this question. I tried to adjust the weights by assigning a weight of 1 to the uninfected individuals and a weight of 15 to the infected, but I obtained poor results. Thank you for your help Yohann [[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.