xgboost/dev/base/xgboost_learner.h
2014-04-10 22:09:19 +08:00

284 lines
11 KiB
C++

#ifndef XGBOOST_LEARNER_H
#define XGBOOST_LEARNER_H
/*!
* \file xgboost_learner.h
* \brief class for gradient boosting learner
* \author Kailong Chen: chenkl198812@gmail.com, Tianqi Chen: tianqi.tchen@gmail.com
*/
#include <cmath>
#include <cstdlib>
#include <cstring>
#include "xgboost_data_instance.h"
#include "../utils/xgboost_omp.h"
#include "../booster/xgboost_gbmbase.h"
#include "../utils/xgboost_utils.h"
#include "../utils/xgboost_stream.h"
namespace xgboost {
namespace base {
/*! \brief class for gradient boosting learner */
class BoostLearner {
public:
/*! \brief constructor */
BoostLearner(void) {
silent = 0;
}
/*!
* \brief booster associated with training and evaluating data
* \param train pointer to the training data
* \param evals array of evaluating data
* \param evname name of evaluation data, used print statistics
*/
BoostLearner(const DMatrix *train,
const std::vector<DMatrix *> &evals,
const std::vector<std::string> &evname) {
silent = 0;
this->SetData(train, evals, evname);
}
/*!
* \brief associate booster with training and evaluating data
* \param train pointer to the training data
* \param evals array of evaluating data
* \param evname name of evaluation data, used print statistics
*/
inline void SetData(const DMatrix *train,
const std::vector<DMatrix *> &evals,
const std::vector<std::string> &evname) {
this->train_ = train;
this->evals_ = evals;
this->evname_ = evname;
// estimate feature bound
int num_feature = (int)(train->data.NumCol());
// assign buffer index
unsigned buffer_size = static_cast<unsigned>(train->Size());
for (size_t i = 0; i < evals.size(); ++i) {
buffer_size += static_cast<unsigned>(evals[i]->Size());
num_feature = std::max(num_feature, (int)(evals[i]->data.NumCol()));
}
char str_temp[25];
if (num_feature > mparam.num_feature) {
mparam.num_feature = num_feature;
sprintf(str_temp, "%d", num_feature);
base_gbm.SetParam("bst:num_feature", str_temp);
}
sprintf(str_temp, "%u", buffer_size);
base_gbm.SetParam("num_pbuffer", str_temp);
if (!silent) {
printf("buffer_size=%u\n", buffer_size);
}
// set eval_preds tmp sapce
this->eval_preds_.resize(evals.size(), std::vector<float>());
}
/*!
* \brief set parameters from outside
* \param name name of the parameter
* \param val value of the parameter
*/
virtual inline void SetParam(const char *name, const char *val) {
if (!strcmp(name, "silent")) silent = atoi(val);
mparam.SetParam(name, val);
base_gbm.SetParam(name, val);
}
/*!
* \brief initialize solver before training, called before training
* this function is reserved for solver to allocate necessary space and do other preparation
*/
inline void InitTrainer(void) {
base_gbm.InitTrainer();
}
/*!
* \brief initialize the current data storage for model, if the model is used first time, call this function
*/
inline void InitModel(void) {
base_gbm.InitModel();
if(!silent) printf("BoostLearner:InitModel Done!\n");
}
/*!
* \brief load model from stream
* \param fi input stream
*/
inline void LoadModel(utils::IStream &fi) {
base_gbm.LoadModel(fi);
utils::Assert(fi.Read(&mparam, sizeof(ModelParam)) != 0);
}
/*!
* \brief DumpModel
* \param fo text file
* \param fmap feature map that may help give interpretations of feature
* \param with_stats whether print statistics as well
*/
inline void DumpModel(FILE *fo, const utils::FeatMap& fmap, bool with_stats) {
base_gbm.DumpModel(fo, fmap, with_stats);
}
/*!
* \brief Dump path of all trees
* \param fo text file
* \param data input data
*/
inline void DumpPath(FILE *fo, const DMatrix &data) {
base_gbm.DumpPath(fo, data.data);
}
/*!
* \brief save model to stream
* \param fo output stream
*/
inline void SaveModel(utils::IStream &fo) const {
base_gbm.SaveModel(fo);
fo.Write(&mparam, sizeof(ModelParam));
}
virtual void EvalOneIter(int iter, FILE *fo = stderr) {}
/*!
* \brief update the model for one iteration
* \param iteration iteration number
*/
inline void UpdateOneIter(int iter) {
this->PredictBuffer(preds_, *train_, 0);
this->GetGradient(preds_, train_->labels, train_->group_index, grad_, hess_);
std::vector<unsigned> root_index;
base_gbm.DoBoost(grad_, hess_, train_->data, root_index);
// printf("xgboost_learner.h:UpdateOneIter\n");
// const unsigned ndata = static_cast<unsigned>(train_->Size());
// #pragma omp parallel for schedule( static )
// for (unsigned j = 0; j < ndata; ++j) {
// printf("haha:%d %f\n",j,base_gbm.Predict(train_->data, j, j));
// }
}
/*! \brief get intransformed prediction, without buffering */
inline void Predict(std::vector<float> &preds, const DMatrix &data) {
preds.resize(data.Size());
const unsigned ndata = static_cast<unsigned>(data.Size());
#pragma omp parallel for schedule( static )
for (unsigned j = 0; j < ndata; ++j) {
preds[j] = base_gbm.Predict(data.data, j, -1);
}
}
public:
/*!
* \brief update the model for one iteration
* \param iteration iteration number
*/
virtual inline void UpdateInteract(std::string action){
this->InteractPredict(preds_, *train_, 0);
int buffer_offset = static_cast<int>(train_->Size());
for (size_t i = 0; i < evals_.size(); ++i) {
std::vector<float> &preds = this->eval_preds_[i];
this->InteractPredict(preds, *evals_[i], buffer_offset);
buffer_offset += static_cast<int>(evals_[i]->Size());
}
if (action == "remove") {
base_gbm.DelteBooster();
return;
}
this->GetGradient(preds_, train_->labels, train_->group_index, grad_, hess_);
std::vector<unsigned> root_index;
base_gbm.DoBoost(grad_, hess_, train_->data, root_index);
this->InteractRePredict(*train_, 0);
buffer_offset = static_cast<int>(train_->Size());
for (size_t i = 0; i < evals_.size(); ++i) {
this->InteractRePredict(*evals_[i], buffer_offset);
buffer_offset += static_cast<int>(evals_[i]->Size());
}
};
protected:
/*! \brief get the intransformed predictions, given data */
inline void InteractPredict(std::vector<float> &preds, const DMatrix &data, unsigned buffer_offset) {
preds.resize(data.Size());
const unsigned ndata = static_cast<unsigned>(data.Size());
#pragma omp parallel for schedule( static )
for (unsigned j = 0; j < ndata; ++j) {
preds[j] = base_gbm.InteractPredict(data.data, j, buffer_offset + j);
}
}
/*! \brief repredict trial */
inline void InteractRePredict(const xgboost::base::DMatrix &data, unsigned buffer_offset) {
const unsigned ndata = static_cast<unsigned>(data.Size());
#pragma omp parallel for schedule( static )
for (unsigned j = 0; j < ndata; ++j) {
base_gbm.InteractRePredict(data.data, j, buffer_offset + j);
}
}
/*! \brief get intransformed predictions, given data */
virtual inline void PredictBuffer(std::vector<float> &preds, const DMatrix &data, unsigned buffer_offset) {
preds.resize(data.Size());
const unsigned ndata = static_cast<unsigned>(data.Size());
#pragma omp parallel for schedule( static )
for (unsigned j = 0; j < ndata; ++j) {
preds[j] = base_gbm.Predict(data.data, j, buffer_offset + j);
}
}
/*! \brief get the first order and second order gradient, given the transformed predictions and labels */
virtual inline void GetGradient(const std::vector<float> &preds,
const std::vector<float> &labels,
const std::vector<int> &group_index,
std::vector<float> &grad,
std::vector<float> &hess) {};
protected:
/*! \brief training parameter for regression */
struct ModelParam {
/* \brief type of loss function */
int loss_type;
/* \brief number of features */
int num_feature;
/*! \brief reserved field */
int reserved[16];
/*! \brief constructor */
ModelParam(void) {
loss_type = 0;
num_feature = 0;
memset(reserved, 0, sizeof(reserved));
}
/*!
* \brief set parameters from outside
* \param name name of the parameter
* \param val value of the parameter
*/
inline void SetParam(const char *name, const char *val) {
if (!strcmp("loss_type", name)) loss_type = atoi(val);
if (!strcmp("bst:num_feature", name)) num_feature = atoi(val);
}
};
int silent;
booster::GBMBase base_gbm;
ModelParam mparam;
const DMatrix *train_;
std::vector<DMatrix *> evals_;
std::vector<std::string> evname_;
std::vector<unsigned> buffer_index_;
std::vector<float> grad_, hess_, preds_;
std::vector< std::vector<float> > eval_preds_;
};
}
};
#endif