ml.dmlc.xgboost4j.java

Class XGBoost

java.lang.Object

ml.dmlc.xgboost4j.java.XGBoost

public class XGBoost
extends Object

trainer for xgboost

Author:

hzx

Constructor Summary

Constructors

Constructor and Description
XGBoost()

Method Summary

Methods

Modifier and Type	Method and Description
static String[]	crossValidation(DMatrix data, Map<String,Object> params, int round, int nfold, String[] metrics, IObjective obj, IEvaluation eval) Cross-validation with given parameters.
static Booster	loadModel(InputStream in) Load a new Booster model from a file opened as input stream.
static Booster	loadModel(String modelPath) load model from modelPath
static Booster	train(DMatrix dtrain, Map<String,Object> params, int round, Map<String,DMatrix> watches, float[][] metrics, IObjective obj, IEvaluation eval, int earlyStoppingRound) Train a booster given parameters.
static Booster	train(DMatrix dtrain, Map<String,Object> params, int round, Map<String,DMatrix> watches, float[][] metrics, IObjective obj, IEvaluation eval, int earlyStoppingRounds, Booster booster) Train a booster given parameters.
static Booster	train(DMatrix dtrain, Map<String,Object> params, int round, Map<String,DMatrix> watches, IObjective obj, IEvaluation eval) Train a booster given parameters.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XGBoost

public XGBoost()

Method Detail

loadModel

public static Booster loadModel(String modelPath)
                         throws XGBoostError

load model from modelPath

Parameters:

modelPath - booster modelPath (model generated by booster.saveModel)

Throws:

XGBoostError - native error

loadModel

public static Booster loadModel(InputStream in)
                         throws XGBoostError,
                                IOException

Load a new Booster model from a file opened as input stream. The assumption is the input stream only contains one XGBoost Model. This can be used to load existing booster models saved by other xgboost bindings.

Parameters:

in - The input stream of the file, will be closed after this function call.

Returns:

The create boosted

Throws:

XGBoostError

IOException

train

public static Booster train(DMatrix dtrain,
            Map<String,Object> params,
            int round,
            Map<String,DMatrix> watches,
            IObjective obj,
            IEvaluation eval)
                     throws XGBoostError

Train a booster given parameters.

Parameters:

dtrain - Data to be trained.

params - Parameters.

round - Number of boosting iterations.

watches - a group of items to be evaluated during training, this allows user to watch performance on the validation set.

obj - customized objective

eval - customized evaluation

Returns:

The trained booster.

Throws:

XGBoostError

train

public static Booster train(DMatrix dtrain,
            Map<String,Object> params,
            int round,
            Map<String,DMatrix> watches,
            float[][] metrics,
            IObjective obj,
            IEvaluation eval,
            int earlyStoppingRound)
                     throws XGBoostError

Train a booster given parameters.

Parameters:

dtrain - Data to be trained.

params - Parameters.

round - Number of boosting iterations.

watches - a group of items to be evaluated during training, this allows user to watch performance on the validation set.

metrics - array containing the evaluation metrics for each matrix in watches for each iteration

earlyStoppingRound - if non-zero, training would be stopped after a specified number of consecutive increases in any evaluation metric.

obj - customized objective

eval - customized evaluation

Returns:

The trained booster.

Throws:

XGBoostError

train

public static Booster train(DMatrix dtrain,
            Map<String,Object> params,
            int round,
            Map<String,DMatrix> watches,
            float[][] metrics,
            IObjective obj,
            IEvaluation eval,
            int earlyStoppingRounds,
            Booster booster)
                     throws XGBoostError

Train a booster given parameters.

Parameters:

dtrain - Data to be trained.

params - Parameters.

round - Number of boosting iterations.

watches - a group of items to be evaluated during training, this allows user to watch performance on the validation set.

metrics - array containing the evaluation metrics for each matrix in watches for each iteration

earlyStoppingRounds - if non-zero, training would be stopped after a specified number of consecutive goes to the unexpected direction in any evaluation metric.

obj - customized objective

eval - customized evaluation

booster - train from scratch if set to null; train from an existing booster if not null.

Returns:

The trained booster.

Throws:

XGBoostError

crossValidation

public static String[] crossValidation(DMatrix data,
                       Map<String,Object> params,
                       int round,
                       int nfold,
                       String[] metrics,
                       IObjective obj,
                       IEvaluation eval)
                                throws XGBoostError

Cross-validation with given parameters.

Parameters:

data - Data to be trained.

params - Booster params.

round - Number of boosting iterations.

nfold - Number of folds in CV.

metrics - Evaluation metrics to be watched in CV.

obj - customized objective (set to null if not used)

eval - customized evaluation (set to null if not used)

Returns:

evaluation history

Throws:

XGBoostError - native error