Re: how does class weights Parameter in LibSVM work?
Yes the Class Weights parameter allows you to manually adjust the class weights. You could set "Yes" = 1 and "No" = 2. The Metacost operator, if memory serves, uses a cost matrix where you can adjust the penalty of mis-classification. Like Predicted True vs Acutal True = 1 and Predicted True vs Actual False = 4.
Regards, Thomas - Community Manager LinkedIn: Thomas Ott