Dear R-society, I know this is probably a question to LibSVM, but I have not found a LibSVM mailing list, so I would be really grateful if someone from this list helped me. In the LibSVM documentation I have found a passage about dealing with unbalanced sets, that says that in this case one sets two different regularization parameters C^{-} and C^{+}. However I am not sure about how this corresponds to the parameters in the svm function. There I find C and class.weights. So am I right supposing that C^{-} = class.weights[1]*C and C^{+} = class.weights[2]*C ? -- Sincerely yours, Yulia Matveyeva, Department of Statistical Modelling, Faculty of Mathematics and Mechanics, St Petersburg State University, Russia [[alternative HTML version deleted]]