xgboost/old_src/tree/updater.h
2016-01-16 10:24:00 -08:00

64 lines
2.0 KiB
C++

/*!
* Copyright 2014 by Contributors
* \file updater.h
* \brief interface to update the tree
* \author Tianqi Chen
*/
#ifndef XGBOOST_TREE_UPDATER_H_
#define XGBOOST_TREE_UPDATER_H_
#include <vector>
#include "../data.h"
#include "./model.h"
namespace xgboost {
namespace tree {
/*!
* \brief interface of tree update module, that performs update of a tree
*/
class IUpdater {
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 perform update to the tree models
* \param gpair the gradient pair statistics of the data
* \param p_fmat feature matrix that provide access to features
* \param info extra side information that may be need, such as root index
* \param trees references the trees to be updated, updater will change the content of trees
* note: all the trees in the vector are updated, with the same statistics,
* but maybe different random seeds, usually one tree is passed in at a time,
* there can be multiple trees when we train random forest style model
*/
virtual void Update(const std::vector<bst_gpair> &gpair,
IFMatrix *p_fmat,
const BoosterInfo &info,
const std::vector<RegTree*> &trees) = 0;
/*!
* \brief this is simply a function for optimizing performance
* this function asks the updater to return the leaf position of each instance in the p_fmat,
* if it is cached in the updater, if it is not available, return NULL
* \return array of leaf position of each instance in the last updated tree
*/
virtual const int* GetLeafPosition(void) const {
return NULL;
}
// destructor
virtual ~IUpdater(void) {}
};
/*!
* \brief create an updater based on name
* \param name name of updater
* \return return the updater instance
*/
IUpdater* CreateUpdater(const char *name);
} // namespace tree
} // namespace xgboost
#endif // XGBOOST_TREE_UPDATER_H_