LogPlusOne.cpp

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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
 */

#include "preproc/LogPlusOne.h"
#include "preproc/SimplePreProc.h"
#include "features/Features.h"
#include "features/SimpleFeatures.h"
#include "lib/Mathematics.h"

using namespace shogun;

CLogPlusOne::CLogPlusOne()
: CSimplePreProc<float64_t>("LogPlusOne", "LG+1")
{
}


CLogPlusOne::~CLogPlusOne()
{
}

bool CLogPlusOne::init(CFeatures* f)
{
    ASSERT(f->get_feature_class()==C_SIMPLE);
    ASSERT(f->get_feature_type()==F_DREAL);

    return true;
}

void CLogPlusOne::cleanup()
{
}

bool CLogPlusOne::load(FILE* f)
{
    SG_SET_LOCALE_C;
    SG_RESET_LOCALE;
    return false;
}

bool CLogPlusOne::save(FILE* f)
{
    SG_SET_LOCALE_C;
    SG_RESET_LOCALE;
    return false;
}

float64_t* CLogPlusOne::apply_to_feature_matrix(CFeatures* f)
{
    int32_t i,j;
    int32_t num_vec;
    int32_t num_feat;
    float64_t* matrix=((CSimpleFeatures<float64_t>*) f)->get_feature_matrix(num_feat, num_vec);

    for (i=0; i<num_vec; i++)
    {
        float64_t* vec=&matrix[i*num_feat];

        for (j=0; j<num_feat; j++)
            vec[j]=log(vec[j]+1);
    }
    return matrix;
}

float64_t* CLogPlusOne::apply_to_feature_vector(float64_t* f, int32_t& len)
{
    float64_t* vec=new float64_t[len];
    int32_t i=0;

    for (i=0; i<len; i++)
        vec[i]=log(f[i]+1);

    return vec;
}