xgboost/gbm/gbm.h
2014-08-15 20:15:58 -07:00

83 lines
2.7 KiB
C++

#ifndef XGBOOST_GBM_GBM_H_
#define XGBOOST_GBM_GBM_H_
/*!
* \file gbm.h
* \brief interface of gradient booster, that learns through gradient statistics
* \author Tianqi Chen
*/
#include <vector>
#include "../data.h"
namespace xgboost {
/*! \brief namespace for gradient booster */
namespace gbm {
/*!
* \brief interface of gradient boosting model
* \tparam FMatrix the data type updater taking
*/
template<typename FMatrix>
class IGradBooster {
public:
/*!
* \brief set parameters from outside
* \param name name of the parameter
* \param val value of the parameter
*/
virtual void SetParam(const char *name, const char *val) = 0;
/*!
* \brief load model from stream
* \param fi input stream
*/
virtual void LoadModel(utils::IStream &fi) = 0;
/*!
* \brief save model to stream
* \param fo output stream
*/
virtual void SaveModel(utils::IStream &fo) const = 0;
/*!
* \brief initialize the model
*/
virtual void InitModel(void) = 0;
/*!
* \brief peform update to the model(boosting)
* \param gpair the gradient pair statistics of the data
* \param fmat feature matrix that provide access to features
* \param root_index pre-partitioned root_index of each instance,
* root_index.size() can be 0 which indicates that no pre-partition involved
*/
virtual void DoBoost(const std::vector<bst_gpair> &gpair,
FMatrix &fmat,
const std::vector<unsigned> &root_index) = 0;
/*!
* \brief generate predictions for given feature matrix
* \param fmat feature matrix
* \param buffer_offset buffer index offset of these instances, if equals -1
* this means we do not have buffer index allocated to the gbm
* a buffer index is assigned to each instance that requires repeative prediction
* the size of buffer is set by convention using IGradBooster.SetParam("num_pbuffer","size")
* \param root_index pre-partitioned root_index of each instance,
* root_index.size() can be 0 which indicates that no pre-partition involved
* \param out_preds output vector to hold the predictions
*/
virtual void Predict(const FMatrix &fmat,
int64_t buffer_offset,
const std::vector<unsigned> &root_index,
std::vector<float> *out_preds) = 0;
// destrcutor
virtual ~IGradBooster(void){}
};
} // namespace gbm
} // namespace xgboost
#include "gbtree-inl.hpp"
namespace xgboost {
namespace gbm {
template<typename FMatrix>
inline IGradBooster<FMatrix>* CreateGradBooster(const char *name) {
if (!strcmp("gbtree", name)) return new GBTree<FMatrix>();
utils::Error("unknown booster type: %s", name);
return NULL;
}
} // namespace gbm
} // namespace xgboost
#endif // XGBOOST_GBM_GBM_H_