GBM 1

#### Train GBM model 1 ####
gbm.ctrl <- trainControl(method = 'repeatedcv',
                         number = 3,
                         summaryFunction = AMS_summary)
gbm.grid <- expand.grid(n.trees = c(50,100,150),
                        interaction.depth = c(1,5,9),
                        shrinkage = c(0.01, 0.005, 0.001),
                        n.minobsinnode = c(10,100,1000))
gbm.model <- train(x = sub.train, y = sub.label, method = 'gbm', weights = sub.weight, 
                   verbose = TRUE, trControl = gbm.ctrl, tuneGrid = gbm.grid, metric = 'AMS')

gbm.model
plot(gbm.model)