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drwnRandomForest Class Reference

Implements a Random forest ensemble of decision trees classifier. See L. Breiman, "Random Forests", Machine Learning, 2001. More...

Inheritance diagram for drwnRandomForest:
drwnClassifier drwnStdObjIface drwnProperties drwnWriteable drwnCloneable drwnTypeable

Public Member Functions

 drwnRandomForest ()
 default constructor
 
 drwnRandomForest (unsigned n, unsigned k=2)
 construct a random forest classifier for k classes and n features
 
 drwnRandomForest (const drwnRandomForest &c)
 copy constructor
 
virtual const char * type () const
 returns object type as a string (e.g., Foo::type() { return "Foo"; })
 
virtual drwnRandomForestclone () const
 returns a copy of the class usually implemented as virtual Foo* clone() { return new Foo(*this); }
 
virtual void initialize (unsigned n, unsigned k=2)
 initialize the classifier object for n features and k classes
 
virtual bool save (drwnXMLNode &node) const
 write object to XML node (see also write)
 
virtual bool load (drwnXMLNode &node)
 read object from XML node (see also read)
 
virtual double train (const drwnClassifierDataset &dataset)
 train the parameters of the classifier from a drwnClassifierDataset object
 
virtual void getClassScores (const vector< double > &features, vector< double > &outputScores) const
 compute the unnormalized log-probability for a single feature vector
 
- Public Member Functions inherited from drwnClassifier
 drwnClassifier ()
 default constructor
 
 drwnClassifier (unsigned n, unsigned k=2)
 construct a classifer with n features and k classes
 
 drwnClassifier (const drwnClassifier &c)
 copy constructor
 
int numFeatures () const
 returns the number of features expected by the classifier object
 
int numClasses () const
 returns the number of classes predicted by the classifier object
 
virtual bool valid () const
 returns true if the classifier is valid (has been initialized and trained)
 
virtual double train (const vector< vector< double > > &features, const vector< int > &targets)
 train the parameters of the classifier from a set of features and corresponding labels
 
virtual double train (const vector< vector< double > > &features, const vector< int > &targets, const vector< double > &weights)
 train the parameters of the classifier from a weighted set of features and corresponding labels
 
virtual double train (const char *filename)
 train the parameters of the classifier from data stored in filename
 
virtual void getClassScores (const vector< vector< double > > &features, vector< vector< double > > &outputScores) const
 compute the unnormalized log-probability for a set of feature vectors
 
virtual void getClassMarginals (const vector< double > &features, vector< double > &outputMarginals) const
 compute the class marginal probabilities for a single feature vector
 
virtual void getClassMarginals (const vector< vector< double > > &features, vector< vector< double > > &outputMarginals) const
 compute the class marginal probabilities for a set of feature vectors
 
virtual int getClassification (const vector< double > &features) const
 return the most likely class label for a single feature vector
 
virtual void getClassifications (const vector< vector< double > > &features, vector< int > &outputLabels) const
 compute the most likely class labels for a set of feature vector
 
- Public Member Functions inherited from drwnWriteable
bool write (const char *filename) const
 write object to file (calls save)
 
bool read (const char *filename)
 read object from file (calls load)
 
void dump () const
 print object's current state to standard output (for debugging)
 
- Public Member Functions inherited from drwnProperties
unsigned numProperties () const
 
bool hasProperty (const string &name) const
 
bool hasProperty (const char *name) const
 
unsigned findProperty (const string &name) const
 
unsigned findProperty (const char *name) const
 
void setProperty (unsigned indx, bool value)
 
void setProperty (unsigned indx, int value)
 
void setProperty (unsigned indx, double value)
 
void setProperty (unsigned indx, const string &value)
 
void setProperty (unsigned indx, const char *value)
 
void setProperty (unsigned indx, const Eigen::VectorXd &value)
 
void setProperty (unsigned indx, const Eigen::MatrixXd &value)
 
void setProperty (const char *name, bool value)
 
void setProperty (const char *name, int value)
 
void setProperty (const char *name, double value)
 
void setProperty (const char *name, const string &value)
 
void setProperty (const char *name, const char *value)
 
void setProperty (const char *name, const Eigen::VectorXd &value)
 
void setProperty (const char *name, const Eigen::MatrixXd &value)
 
string getPropertyAsString (unsigned indx) const
 
drwnPropertyType getPropertyType (unsigned indx) const
 
bool isReadOnly (unsigned indx) const
 
const drwnPropertyInterfacegetProperty (unsigned indx) const
 
const drwnPropertyInterfacegetProperty (const char *name) const
 
bool getBoolProperty (unsigned indx) const
 
int getIntProperty (unsigned indx) const
 
double getDoubleProperty (unsigned indx) const
 
const string & getStringProperty (unsigned indx) const
 
const list< string > & getListProperty (unsigned indx) const
 
int getSelectionProperty (unsigned indx) const
 
const Eigen::VectorXd & getVectorProperty (unsigned indx) const
 
const Eigen::MatrixXd & getMatrixProperty (unsigned indx) const
 
const string & getPropertyName (unsigned indx) const
 
vector< string > getPropertyNames () const
 
void readProperties (drwnXMLNode &xml, const char *tag="property")
 
void writeProperties (drwnXMLNode &xml, const char *tag="property") const
 
void printProperties (ostream &os) const
 

Static Public Attributes

static int NUM_TREES = 100
 default number of trees in the forest (used during construction)
 
static int MAX_DEPTH = 2
 default depth of each tree (used during construction)
 
static int MAX_FEATURES = 10
 maximum number of features to use at each iteration (used during construction)
 

Protected Attributes

int _numTrees
 number of trees to learn
 
int _maxDepth
 maximum depth of each decision tree
 
int _maxFeatures
 maximum number of features to use at each iteration
 
vector< drwnDecisionTree * > _forest
 forest
 
vector< double > _alphas
 weight for each weak tree
 
- Protected Attributes inherited from drwnClassifier
int _nFeatures
 number of features
 
int _nClasses
 number of classes
 
bool _bValid
 true if the classifier has been trained or loaded
 

Additional Inherited Members

- Protected Member Functions inherited from drwnProperties
void declareProperty (const string &name, drwnPropertyInterface *optif)
 
void undeclareProperty (const string &name)
 
void exposeProperties (drwnProperties *opts, const string &prefix=string(""), bool bSerializable=false)
 
virtual void propertyChanged (const string &name)
 

Detailed Description

Implements a Random forest ensemble of decision trees classifier. See L. Breiman, "Random Forests", Machine Learning, 2001.

The following code snippet shows example learning a random forest classifier on a training dataset and then testing it on a hold out evaluation dataset.

// load training dataset
dataset.read("training_data.bin");
// train the classifier
const int nFeatures = dataset.numFeatures();
const int nClasses = dataset.maxTarget() + 1;
drwnRandomForest model(nFeatures, nClasses);
model.train(dataset);
// load evaluation set
dataset.read("testing_data.bin", false);
// predict labels
vector<int> predictions;
model.getClassifications(dataset.features, predictions);

The documentation for this class was generated from the following files: