schwefel.cpp

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 *   Copyright (C) 2004-2015 The PaGMO development team,                     *
 *   Advanced Concepts Team (ACT), European Space Agency (ESA)               *
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#include <boost/math/constants/constants.hpp>
#include <cmath>
#include <string>

#include "../exceptions.h"
#include "../types.h"
#include "base.h"
#include "schwefel.h"

namespace pagmo { namespace problem {


schwefel::schwefel(int n):base(n)
{
        // Set bounds.
        set_lb(-500);
        set_ub(500);
}

base_ptr schwefel::clone() const
{
        return base_ptr(new schwefel(*this));
}

void schwefel::objfun_impl(fitness_vector &f, const decision_vector &x) const
{
        pagmo_assert(f.size() == 1);
        std::vector<double>::size_type n = x.size();
        double value=0;

        for (std::vector<double>::size_type i=0; i<n; i++){
                value += x[i] * sin(sqrt(fabs(x[i])));
                }
                f[0] = 418.9828872724338 * n - value;
}

std::string schwefel::get_name() const
{
        return "Schwefel";
}

}}

BOOST_CLASS_EXPORT_IMPLEMENT(pagmo::problem::schwefel)