Hello, I trying to find a way to calculate a bivariate bandwidth for a bivariate local polynomial regression and I have a question. Somebody know if I can use the instruction "dpill" to do it? When I read the instructions I see that "x" must be a vector of variables, but if I state "x" is a matrix with 2 columns the program also works. Please, somebody can help me? Thanks a lot Alexandra [[alternative HTML version deleted]]