inventory.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 "../population.h"
#include "../rng.h"
#include "../types.h"
#include "base_stochastic.h"
#include "inventory.h"

namespace pagmo { namespace problem {

inventory::inventory(int weeks,int sample_size, unsigned int seed) : base_stochastic(weeks,seed),
        m_weeks(weeks),m_sample_size(sample_size)
{
        set_lb(0.0);
        set_ub(200.0);
}

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

void inventory::objfun_impl(fitness_vector &f, const decision_vector &x) const
{
        m_drng.seed(m_seed);
        const double c=1.0,b=1.5,h=0.1;
        double retval=0;

        for (size_t i = 0; i<m_sample_size; ++i) {
                double I=0;
                for (decision_vector::size_type j = 0; j<x.size(); ++j) {
                        double d = m_drng() * 100;
                        retval += c * x[j] + b * std::max<double>(d-I-x[j],0) + h * std::max<double>(I+x[j]-d,0);
                        I = std::max<double>(0, I + x[j] - d);
                }
        }
        f[0] = retval / m_sample_size;
}


std::string inventory::human_readable_extra() const
{
        std::ostringstream oss;
        oss << "\n\tWeeks: " << m_weeks << '\n';
        oss << "\tSample Size: " << m_sample_size << '\n';
        oss << "\tSeed: " << m_seed << '\n';
        return oss.str();
}

std::string inventory::get_name() const
{
        return "Inventory";
}

}} //namespaces

BOOST_CLASS_EXPORT_IMPLEMENT(pagmo::problem::inventory)