GradientEvaluation.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) 2013 Roman Votyakov
 * Copyright (C) 2012 Jacob Walker
 */

#include <shogun/evaluation/GradientEvaluation.h>
#include <shogun/evaluation/GradientResult.h>

using namespace shogun;

CGradientEvaluation::CGradientEvaluation() : CMachineEvaluation()
{
    init();
}

CGradientEvaluation::CGradientEvaluation(CMachine* machine, CFeatures* features,
        CLabels* labels, CEvaluation* evaluation_crit, bool autolock) :
        CMachineEvaluation(machine, features, labels, NULL, evaluation_crit, autolock)
{
    init();
}

void CGradientEvaluation::init()
{
    m_diff=NULL;
    m_parameter_dictionary=NULL;

    SG_ADD((CSGObject**)&m_diff, "differentiable_function", "Differentiable "
            "function", MS_AVAILABLE);
}

CGradientEvaluation::~CGradientEvaluation()
{
    SG_UNREF(m_diff);
    SG_UNREF(m_parameter_dictionary);
}

void CGradientEvaluation::update_parameter_dictionary()
{
    SG_UNREF(m_parameter_dictionary);

    m_parameter_dictionary=new CMap<TParameter*, CSGObject*>();
    m_diff->build_gradient_parameter_dictionary(m_parameter_dictionary);
    SG_REF(m_parameter_dictionary);
}

CEvaluationResult* CGradientEvaluation::evaluate()
{
    if (parameter_hash_changed())
        update_parameter_dictionary();

    // create gradient result object
    CGradientResult* result=new CGradientResult();
    SG_REF(result);

    // set function value
    result->set_value(m_diff->get_value());

    CMap<TParameter*, SGVector<float64_t> >* gradient=m_diff->get_gradient(
            m_parameter_dictionary);

    // set gradient and parameter dictionary
    result->set_gradient(gradient);
    result->set_paramter_dictionary(m_parameter_dictionary);

    SG_UNREF(gradient);

    update_parameter_hash();

    return result;
}