I am trying to learn to tune a svm model in R. I'm using the sonar data set used by David Mease in his Google Tech Talk video. I downloaded the data from his site. There are 130 observations in the training set. I am able to run a svm model. But when I try to run this command: tune_svm <-tune.svm(y~., data=x, gamma=10^(-6:-3), cost=10^(1:2)) where y is the categorical response vector for the training set and x is the training data for x, I get the following error: Error in model.frame.default(formula, data) : variable lengths differ (found for 'V1') I've doublechecked that all the data is the same length. I cleared the workspace to make sure that I didn't have any other data labeled as x or y. Can someone tell me what I am doing wrong here? Thanks.