ID3ClassifierTree.h

Go to the documentation of this file.

/*
 * Copyright (c) The Shogun Machine Learning Toolbox
 * Written (w) 2014 Parijat Mazumdar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those
 * of the authors and should not be interpreted as representing official policies,
 * either expressed or implied, of the Shogun Development Team.
 */


#ifndef _ID3CLASSIFIERTREE_H__
#define _ID3CLASSIFIERTREE_H__

#include <shogun/lib/config.h>

#include <shogun/multiclass/tree/TreeMachine.h>
#include <shogun/multiclass/tree/ID3TreeNodeData.h>
#include <shogun/features/DenseFeatures.h>
#include <shogun/labels/MulticlassLabels.h>

namespace shogun
{

class CID3ClassifierTree : public CTreeMachine<id3TreeNodeData>
{
public:
    CID3ClassifierTree();

    virtual ~CID3ClassifierTree();

    virtual const char* get_name() const { return "ID3ClassifierTree"; }

    virtual CMulticlassLabels* apply_multiclass(CFeatures* data=NULL);

    bool prune_tree(CDenseFeatures<float64_t>* validation_data, CMulticlassLabels* validation_labels, float64_t epsilon=0.f);

protected:

    virtual bool train_machine(CFeatures* data=NULL);

private:

    node_t* id3train(CFeatures* data, CMulticlassLabels* class_labels, SGVector<int32_t> values, int level = 0);

    float64_t informational_gain_attribute(int32_t attr_no, CFeatures* data, CMulticlassLabels* class_labels);

    float64_t entropy(CMulticlassLabels* labels);

    void prune_tree_machine(CDenseFeatures<float64_t>* feats, CMulticlassLabels* gnd_truth, node_t* current, float64_t epsilon);

    CMulticlassLabels* apply_multiclass_from_current_node(CDenseFeatures<float64_t>* feats, node_t* current);
};
} /* namespace shogun */

#endif /* _ID3CLASSIFIERTREE_H__ */