migration/base.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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 *   https://github.com/esa/pagmo                                            *
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 *   act@esa.int                                                             *
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#include <boost/numeric/conversion/cast.hpp>
#include <climits>
#include <iostream>
#include <sstream>
#include <string>
#include <typeinfo>

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

namespace pagmo { namespace migration {


base::base(const double &rate, rate_type type):m_rate(rate),m_type(type)
{
        switch (m_type) {
                case absolute:
                        if (m_rate < 0 || m_rate > INT_MAX) {
                                pagmo_throw(value_error,"invalid absolute migration rate");
                        }
                        // Convert to nearest integer.
                        m_rate = double_to_int::convert(m_rate);
                        break;
                case fractional:
                        if (m_rate < 0 || m_rate > 1) {
                                pagmo_throw(value_error,"invalid fractional migration rate");
                        }
                        break;
                default:
                        pagmo_throw(value_error,"invalid type for migration rate");
        }
}


population::size_type base::get_n_individuals(const population &pop) const
{
        population::size_type retval = 0;
        switch (m_type) {
                case absolute:
                        retval = boost::numeric_cast<population::size_type>(m_rate);
                        if (retval > pop.size()) {
                                pagmo_throw(value_error,"absolute migration rate is higher than population size");
                        }
                        break;
                case fractional:
                        retval = boost::numeric_cast<population::size_type>(double_to_int::convert(m_rate * pop.size()));
                        pagmo_assert(retval <= pop.size());
        }
        return retval;
}


std::string base::human_readable() const
{
        std::ostringstream oss;
        oss << "Policy name: " << typeid(*this).name() << '\n';
        oss << "\tMigration type: " << ((m_type) ? "fractional" : "absolute") << '\n';
        oss << "\tMigration rate: " << ((m_type) ? (m_rate * 100) : m_rate) << ((m_type) ? "%" : "") << '\n';
        oss << human_readable_extra();
        return oss.str();
}


std::string base::human_readable_extra() const
{
        return std::string();
}


std::ostream &operator<<(std::ostream &s, const base &p)
{
        s << p.human_readable();
        return s;
}


base::~base()
{}

}}