I'm a new user of ENVI 5.1. I have a question about the implementation of the supervised classification method SVM. I'm trying to run grid search cross-validation in order to identify the optimal C and gamma parameters for the RBF kernel. Here are my questions: 1- How to select best kernel parameters for Radial basis function of SVM by grid search cross-validation using ENVI 5.1? 2- I have sample areas. How do I separate these sample areas as training set, cross validation set and test set?