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 <shogun/preprocessor/LogPlusOne.h>
#include <shogun/preprocessor/DensePreprocessor.h>
#include <shogun/features/Features.h>
#include <shogun/mathematics/Math.h>

using namespace shogun;

CLogPlusOne::CLogPlusOne()
: CDensePreprocessor<float64_t>()
{
}


CLogPlusOne::~CLogPlusOne()
{
}

bool CLogPlusOne::init(CFeatures* features)
{
    ASSERT(features->get_feature_class()==C_DENSE);
    ASSERT(features->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;
}

SGMatrix<float64_t> CLogPlusOne::apply_to_feature_matrix(CFeatures* features)
{
    SGMatrix<float64_t> feature_matrix =
            ((CDenseFeatures<float64_t>*)features)->get_feature_matrix();

    for (int32_t i=0; i<feature_matrix.num_cols; i++)
    {
        for (int32_t j=0; j<feature_matrix.num_rows; j++)
            feature_matrix.matrix[i*feature_matrix.num_rows+j] =
                    CMath::log(feature_matrix.matrix[i*feature_matrix.num_rows+j]+1.0);
    }
    return feature_matrix;
}

SGVector<float64_t> CLogPlusOne::apply_to_feature_vector(SGVector<float64_t> vector)
{
    float64_t* log_vec = SG_MALLOC(float64_t, vector.vlen);

    for (int32_t i=0; i<vector.vlen; i++)
        log_vec[i]=CMath::log(vector.vector[i]+1.0);

    return SGVector<float64_t>(log_vec,vector.vlen);
}