basic caret demo with ROC

gistfile1.r

library(mlbench)
library(caret)
data(Sonar)
inTraining <- createDataPartition(Sonar$Class, p = 0.75, list = FALSE)
training <- Sonar[inTraining, ]
testing <- Sonar[-inTraining, ]

myTuneGrid <- expand.grid(n.trees = 500,interaction.depth = 11,shrinkage = 0.1)

fitControl <- trainControl(method = "repeatedcv", 
                           number = 7,
                           repeats = 1, 
                           verboseIter = FALSE,
                           returnResamp = "all",
                           classProbs = TRUE,
                           summaryFunction=twoClassSummary)

set.seed(825)
gbmFit1 <- train(Class ~ ., data = training,
                 method = "gbm",
                 trControl = fitControl,
                 verbose = FALSE,
                 metric="ROC",
                 tuneGrid=myTuneGrid)