diff --git a/R-package/NAMESPACE b/R-package/NAMESPACE index 491231a11..a13e64931 100644 --- a/R-package/NAMESPACE +++ b/R-package/NAMESPACE @@ -1,6 +1,7 @@ # Generated by roxygen2 (4.0.1): do not edit by hand export(getinfo) +export(setinfo) export(slice) export(xgb.DMatrix) export(xgb.DMatrix.save) diff --git a/R-package/demo/README.md b/R-package/demo/README.md new file mode 100644 index 000000000..f164649d8 --- /dev/null +++ b/R-package/demo/README.md @@ -0,0 +1,8 @@ +XGBoost R Feature Walkthrough +==== +* [Basic walkthrough of wrappers](basic_walkthrough.R) +* [Cutomize loss function, and evaluation metric](custom_objective.R) +* [Boosting from existing prediction](boost_from_prediction.R) +* [Predicting using first n trees](predict_first_ntree.py) +* [Generalized Linear Model](generalized_linear_model.py) +* [Cross validation](cross_validation.py) diff --git a/R-package/demo/boost_from_prediction.R b/R-package/demo/boost_from_prediction.R new file mode 100644 index 000000000..7372717f8 --- /dev/null +++ b/R-package/demo/boost_from_prediction.R @@ -0,0 +1,26 @@ +require(xgboost) +# load in the agaricus dataset +data(agaricus.train, package='xgboost') +data(agaricus.test, package='xgboost') +dtrain <- xgb.DMatrix(agaricus.train$data, label = agaricus.train$label) +dtest <- xgb.DMatrix(agaricus.test$data, label = agaricus.test$label) + +watchlist <- list(eval = dtest, train = dtrain) +### +# advanced: start from a initial base prediction +# +print('start running example to start from a initial prediction') +# train xgboost for 1 round +param <- list(max_depth=2,eta=1,silent=1,objective='binary:logistic') +bst <- xgb.train( param, dtrain, 1, watchlist ) +# Note: we need the margin value instead of transformed prediction in set_base_margin +# do predict with output_margin=TRUE, will always give you margin values before logistic transformation +ptrain <- predict(bst, dtrain, outputmargin=TRUE) +ptest <- predict(bst, dtest, outputmargin=TRUE) +# set the base_margin property of dtrain and dtest +# base margin is the base prediction we will boost from +setinfo(dtrain, "base_margin", ptrain) +setinfo(dtest, "base_margin", ptest) + +print('this is result of boost from initial prediction') +bst <- xgb.train( param, dtrain, 1, watchlist )