LinearClassifier.h

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/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * Written (W) 1999-2009 Soeren Sonnenburg
 * Copyright (C) 1999-2009 Fraunhofer Institute FIRST and Max-Planck-Society
 */

#ifndef _LINEARCLASSIFIER_H__
#define _LINEARCLASSIFIER_H__

#include "lib/common.h"
#include "features/Labels.h"
#include "features/DotFeatures.h"
#include "classifier/Classifier.h"

#include <stdio.h>

namespace shogun
{
    class CDotFeatures;
    class CLabels;

class CLinearClassifier : public CClassifier
{
    public:
        CLinearClassifier();
        virtual ~CLinearClassifier();

        virtual inline float64_t classify_example(int32_t vec_idx)
        {
            return features->dense_dot(vec_idx, w, w_dim) + bias;
        }

        inline void get_w(float64_t*& dst_w, int32_t& dst_dims)
        {
            ASSERT(w && w_dim>0);
            dst_w=w;
            dst_dims=w_dim;
        }

        inline void get_w(float64_t** dst_w, int32_t* dst_dims)
        {
            ASSERT(dst_w && dst_dims);
            ASSERT(w && w_dim>0);
            *dst_dims=w_dim;
            *dst_w=(float64_t*) malloc(sizeof(float64_t)*(*dst_dims));
            ASSERT(*dst_w);
            memcpy(*dst_w, w, sizeof(float64_t) * (*dst_dims));
        }

        inline void set_w(float64_t* src_w, int32_t src_w_dim)
        {
            delete[] w;
            w=new float64_t[src_w_dim];
            memcpy(w, src_w, size_t(src_w_dim)*sizeof(float64_t));
            w_dim=src_w_dim;
        }

        inline void set_bias(float64_t b)
        {
            bias=b;
        }

        inline float64_t get_bias()
        {
            return bias;
        }

        virtual bool load(FILE* srcfile);

        virtual bool save(FILE* dstfile);

        virtual inline void set_features(CDotFeatures* feat)
        {
            SG_UNREF(features);
            SG_REF(feat);
            features=feat;
        }

        virtual CLabels* classify();

        virtual CLabels* classify(CFeatures* data);

        virtual CDotFeatures* get_features() { SG_REF(features); return features; }

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

    protected:
        int32_t w_dim;
        float64_t* w;
        float64_t bias;
        CDotFeatures* features;
};
}
#endif