first commit

include/LightGBM/tree_learner.h

+#ifndef LIGHTGBM_TREE_LEARNER_H_
+#define LIGHTGBM_TREE_LEARNER_H_
+
+
+#include <LightGBM/meta.h>
+#include <LightGBM/config.h>
+
+#include <vector>
+
+namespace LightGBM {
+
+/*! \brief forward declaration */
+class Tree;
+class Dataset;
+
+/*!
+* \brief Interface for tree learner
+*/
+class TreeLearner {
+public:
+  /*! \brief virtual destructor */
+  virtual ~TreeLearner() {}
+
+  /*!
+  * \brief Init tree learner with training data set and tree config
+  * \param train_data The used training data
+  * \param tree_config The tree setting
+  */
+  virtual void Init(const Dataset* train_data) = 0;
+
+  /*!
+  * \brief fit train data set and return a trained tree
+  * \param gradients The first order gradients
+  * \param hessians The second order gradients
+  * \return A trained tree
+  */
+  virtual Tree* Train(const score_t* gradients, const score_t* hessians) = 0;
+
+  /*!
+  * \brief SetLabelAt bagging data
+  * \param used_indices Used data indices
+  * \param num_data Number of used data
+  */
+  virtual void SetBaggingData(const data_size_t* used_indices,
+    data_size_t num_data) = 0;
+
+  /*!
+  * \brief Use last trained tree to predition training score, and add to out_score;
+  * \param out_score output score
+  */
+  virtual void AddPredictionToScore(score_t *out_score) const = 0;
+
+  /*!
+  * \brief Create object of tree learner
+  * \param type Type of tree learner
+  */
+  static TreeLearner* CreateTreeLearner(TreeLearnerType type,
+    const TreeConfig& tree_config);
+};
+
+}  // namespace LightGBM
+
+#endif  #endif  // LightGBM_TREE_LEARNER_H_