expenditure_components.h

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// SPDX-FileCopyrightText: 2020 W. Traylor <wolfgang.traylor@senckenberg.de>
//
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#ifndef FAUNA_EXPENDITURE_COMPONENTS_H
#define FAUNA_EXPENDITURE_COMPONENTS_H
 
#include <assert.h>
#include <cmath>
#include <stdexcept>
 
namespace Fauna {
 
inline double get_expenditure_taylor_1981(const double current_bodymass,
                                          const double adult_bodymass) {
  return 0.4 * current_bodymass * pow(adult_bodymass, -0.27);
}
 
 
inline double get_expenditure_zhu_et_al_2018(const double bodymass,
                                             const double ambient_temperature) {
  if (bodymass <= 0)
    throw std::invalid_argument(
        "Fauna::get_expenditure_zhu_et_al_2018() "
        "Parameter `bodymass` is <=0.");
  const double k1 = 0.0079;
  const double k2 = 0.36;
  return k2 / (exp(k1 * ambient_temperature)) * pow(bodymass, 0.75);
}
 
inline double watts_to_MJ_per_day(const double W) {
  return W * 24 * 3600 * 10e-6;
}
 
 
inline double get_conductance_bradley_deavers_1980(const double bodymass) {
  if (bodymass <= 0.0)
    throw std::invalid_argument(
        "Fauna::get_conductance_bradley_deavers_1980() "
        "Parameter `bodymass` is <=0.");
  return 0.224 * pow(bodymass, 0.574);
}
 
enum class FurSeason {
  Summer,
  Winter
};
 
 
inline double get_conductance_cuyler_oeritsland_2004(const double bodymass,
                                                     const FurSeason season) {
  if (bodymass <= 0.0)
    throw std::invalid_argument(
        "Fauna::get_conductance_cuyler_oeritsland_2004() "
        "Parameter `bodymass` is <=0.");
  assert((season == FurSeason::Summer) || (season == FurSeason::Winter));
  if (season == FurSeason::Summer)
    return 0.29 * pow(bodymass, 0.57);
  else  // Winter:
    return 0.08 * pow(bodymass, 0.57);
}
 
 
double get_thermoregulatory_expenditure(const double thermoneutral_rate,
                                        const double conductance,
                                        const double core_temperature,
                                        const double ambient_temperature);
}  // namespace Fauna
 
#endif  // FAUNA_EXPENDITURE_COMPONENTS_H