constants.h

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/* Copyright (C) 2019
 * Richard Larsson <ric.larsson@gmail.com>
 * 
 * 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 2, or (at your option) any
 * later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA. */

#ifndef CONSTANTS_IN_ARTS_H
#define CONSTANTS_IN_ARTS_H

#include <cmath>
#include "matpack.h"

namespace Constant {
template <class T>
constexpr T pow2(T x) {
  return x * x;
}

template <class T>
constexpr T pow3(T x) {
  return pow2(x) * x;
}

template <class T>
constexpr T pow4(T x) {
  return pow2(pow2(x));
}

static constexpr Numeric pi =
    3.141592653589793238462643383279502884197169399375105820974944592307816406286;

static constexpr Numeric inv_pi =
    0.3183098861837906715377675267450287240689192914809128974953346881177935952685;

static constexpr Numeric two_pi =
    6.283185307179586476925286766559005768394338798750211641949889184615632812572;

static constexpr Numeric inv_two_pi =
    0.1591549430918953357688837633725143620344596457404564487476673440588967976342;

static constexpr Numeric sqrt_pi =
    1.772453850905516027298167483341145182797549456122387128213807789852911284591;

static constexpr Numeric inv_sqrt_pi =
    0.5641895835477562869480794515607725858440506293289988568440857217106424684415;

static constexpr Numeric euler =
    2.718281828459045235360287471352662497757247093699959574966967627724076630354;

static constexpr Numeric inv_euler =
    0.3678794411714423215955237701614608674458111310317678345078368016974614957448;

static constexpr Numeric log10_euler =
    0.4342944819032518276511289189166050822943970058036665661144537831658646492089;

static constexpr Numeric ln_10 =
    2.302585092994045684017991454684364207601101488628772976033327900967572609677;

static constexpr Numeric sqrt_2 =
    1.414213562373095048801688724209698078569671875376948073176679737990732478462;

static constexpr Numeric inv_sqrt_2 =
    0.7071067811865475244008443621048490392848359376884740365883398689953662392311;

static constexpr Numeric ln_2 =
    0.6931471805599453094172321214581765680755001343602552541206800094933936219697;

static constexpr Numeric inv_ln_2 =
    1.442695040888963407359924681001892137426645954152985934135449406931109219181;

static constexpr Numeric sqrt_ln_2 =
    0.8325546111576977563531646448952010476305888522644407291668291172340794351973;

static constexpr Numeric inv_sqrt_ln_2 =
    1.201122408786449794857803286095221722566764028068699423868879896733837175546;

static constexpr Numeric Delta_nu_Cs = 9192631770;

static constexpr Numeric speed_of_light = 299792458;

static constexpr Numeric c = speed_of_light;

static constexpr Numeric planck_constant = 6.62607015e-34;

static constexpr Numeric h = planck_constant;

static constexpr Numeric reduced_planck_constant = h * inv_two_pi;

static constexpr Numeric h_bar = reduced_planck_constant;

static constexpr Numeric elementary_charge = 1.602176634e-19;

static constexpr Numeric e = elementary_charge;

static constexpr Numeric boltzmann_constant = 1.380649e-23;

static constexpr Numeric k = boltzmann_constant;

static constexpr Numeric avogadro_constant = 6.02214076e23;

static constexpr Numeric NA = avogadro_constant;

static constexpr Numeric K_cd = 683;

static constexpr Numeric fine_structure_constant = 7.2973525693e-3;

static constexpr Numeric alpha = fine_structure_constant;

static constexpr Numeric rydberg_constant = 10973731.568160;

static constexpr Numeric R_inf = rydberg_constant;

static constexpr Numeric magnetic_constant = 2 * h * alpha / (c * pow2(e));

static constexpr Numeric mu_0 = magnetic_constant;

static constexpr Numeric vacuum_permittivity = pow2(e) / (2 * h * c * alpha);

static constexpr Numeric epsilon_0 = vacuum_permittivity;

static constexpr Numeric electron_mass = 2 * h * R_inf / (c * pow2(alpha));

static constexpr Numeric m_e = electron_mass;

static constexpr Numeric unified_atomic_mass_unit = 1.66053906660e-27;

static constexpr Numeric m_u = unified_atomic_mass_unit;

static constexpr Numeric mass_ratio_electrons_per_proton = 1'836.152'673'43;

static constexpr Numeric proton_mass = electron_mass * mass_ratio_electrons_per_proton;

static constexpr Numeric mass_ratio_electrons_per_neutron = 1'838.683'661'73;

static constexpr Numeric neutron_mass = electron_mass * mass_ratio_electrons_per_neutron;

static constexpr Numeric bohr_magneton = e * h_bar / (2 * m_e);

static constexpr Numeric ideal_gas_constant = k * NA;

static constexpr Numeric R = ideal_gas_constant;

static constexpr Numeric doppler_broadening_const_squared = 2000 * R / pow2(c);
};  // namespace Constant

namespace Conversion {
using namespace Constant;

static constexpr Numeric DEG2RAD = pi / 180;
static constexpr Numeric RAD2DEG = 1 / DEG2RAD;
template <class T>
constexpr Numeric deg2rad(T x) {
  return x * DEG2RAD;
}

template <class T>
constexpr Numeric rad2deg(T x) {
  return x * RAD2DEG;
}

template <class T>
Numeric cosd(T x) {
  return std::cos(deg2rad(x));
}

template <class T>
Numeric sind(T x) {
  return std::sin(deg2rad(x));
}

template <class T>
Numeric tand(T x) {
  return std::tan(deg2rad(x));
}

template <class T>
Numeric acosd(T x) {
  return rad2deg(std::acos(x));
}

template <class T>
Numeric asind(T x) {
  return rad2deg(std::asin(x));
}

template <class T>
Numeric atand(T x) {
  return rad2deg(std::atan(x));
}

template <class T1, class T2>
Numeric atan2d(T1 y, T2 x) {
  return rad2deg(std::atan2(y, x));
}

static constexpr Numeric KAYCM2FREQ = 100 * c;
static constexpr Numeric FREQ2KAYCM = 1 / KAYCM2FREQ;
template <class T>
constexpr Numeric kaycm2freq(T x) {
  return x * KAYCM2FREQ;
}
template <class T>
constexpr Numeric freq2kaycm(T x) {
  return x * FREQ2KAYCM;
}

static constexpr Numeric ANGCM2FREQ = KAYCM2FREQ * inv_two_pi;
static constexpr Numeric FREQ2ANGCM = 1 / ANGCM2FREQ;
template <class T>
constexpr Numeric angcm2freq(T x) {
  return x * ANGCM2FREQ;
}
template <class T>
constexpr Numeric freq2angcm(T x) {
  return x * FREQ2ANGCM;
}

template <class T>
constexpr Numeric angfreq2freq(T x) {
  return x * inv_two_pi;
}
template <class T>
constexpr Numeric freq2angfreq(T x) {
  return x * two_pi;
}

template <class T>
constexpr Numeric wavelen2freq(T x) {
  return c / x;
}
template <class T>
constexpr Numeric freq2wavelen(T x) {
  return c / x;
}

static constexpr Numeric ATM2PA = 101325;
static constexpr Numeric PA2ATM = 1 / ATM2PA;
template <class T>
constexpr Numeric atm2pa(T x) {
  return x * ATM2PA;
}
template <class T>
constexpr Numeric pa2atm(T x) {
  return x * PA2ATM;
}

static constexpr Numeric TORR2PA = ATM2PA / 760;
static constexpr Numeric PA2TORR = 1 / TORR2PA;
template <class T>
constexpr Numeric torr2pa(T x) {
  return x * TORR2PA;
}
template <class T>
constexpr Numeric pa2torr(T x) {
  return x * PA2TORR;
}

static constexpr Numeric CEL2KEL = 273.15;
template <class T>
constexpr Numeric celsius2kelvin(T x) {
  return x + CEL2KEL;
}
template <class T>
constexpr Numeric kelvin2celsius(T x) {
  return x - CEL2KEL;
}

static constexpr Numeric HITRAN2ARTS_LS = KAYCM2FREQ * 1e-4;
static constexpr Numeric ARTS2HITRAN_LS = 1 / HITRAN2ARTS_LS;
template <class T>
constexpr T hitran2arts_linestrength(T x) {
  return x * HITRAN2ARTS_LS;
}
template <class T>
constexpr T arts2hitran_linestrength(T x) {
  return x * ARTS2HITRAN_LS;
}

static constexpr Numeric HITRAN2ARTS_GAMMA = KAYCM2FREQ / ATM2PA;
static constexpr Numeric ARTS2HITRAN_GAMMA = 1 / HITRAN2ARTS_GAMMA;
template <class T>
constexpr T hitran2arts_broadening(T x) {
  return x * HITRAN2ARTS_GAMMA;
}
template <class T>
constexpr T arts2hitran_broadening(T x) {
  return x * ARTS2HITRAN_GAMMA;
}

static constexpr Numeric HITRAN2ARTS_ENERGY = h * KAYCM2FREQ;
static constexpr Numeric ARTS2HITRAN_ENERGY = 1 / HITRAN2ARTS_ENERGY;
template <class T>
constexpr T hitran2arts_energy(T x) {
  return x * HITRAN2ARTS_ENERGY;
}
template <class T>
constexpr T arts2hitran_energy(T x) {
  return x * ARTS2HITRAN_ENERGY;
}

template <class T>
constexpr T angstrom2meter(T x) {
  return x * 1e-10;
}
template <class T>
constexpr T meter2angstrom(T x) {
  return x * 1e10;
}
};  // namespace Conversion

#endif