Transform x together with "category" in new x so that randomForest does not mix them up

surrogateMultiplexWrapper.R

surrogate.learner = makeLearner("regr.randomForest", predict.type = "se")

myTrafo = function(data, target, category, na.val) {
  catf("run mytrafon on data with")
  data.notarget = data[, colnames(data) != target, drop = FALSE]
  data = cbind(dcast(data.notarget, as.formula(paste0("seq_along(", category, ")~",category)), fill = na.val, value.var = "x", drop = FALSE)[, -1, drop = FALSE], data[,colnames(data) %in% c(category, target), drop = FALSE])
  return(data)
}
wrpTrain = function(data, target, args) {
  data = myTrafo(data = data, target = target, category = args$category, na.val = args$na.val)
  list(data = data, control = list())
}
wrpPredict = function(data, target, args, control) {
  myTrafo(data = data, target = target, category = args$category, na.val = args$na.val)
}
surrogate.learner = makePreprocWrapper(learner = surrogate.learner, train = wrpTrain, predict = wrpPredict, par.vals = list(category = "category", na.val = 1024))