I know that sklearn.ensemble.GradientBoostingRegressor supports quantile regression and the production of prediction intervals. Are there any plans for the XGBoost package to offer similar support?
Quantile regression is currently not supported.
It can be achieved by defining the objective function on user's side: https://github.com/dmlc/xgboost/blob/master/R-package/demo/custom_objective.R
Quantile regression with xgboost requires custom gradient and hessian functions. Here is an implementation in Python: http://www.bigdatarepublic.nl/regression-prediction-intervals-with-xgboost/
Note that implementation is not very useful for most users, since it specifies grid-searching three parameters (very costly) to get a quantile estimate. In sklearn, you define only the quantile value and you are given a very robust and reliable estimate of that quantile.
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Quantile regression with xgboost requires custom gradient and hessian functions. Here is an implementation in Python: http://www.bigdatarepublic.nl/regression-prediction-intervals-with-xgboost/