scatt/tests/test_bulk_sphere.cc

#include <complex>
#include "../src/mesomie.hpp"
#include "../src/nmie-basic.hpp"
#include "gtest/gtest.h"

// TODO fails for MP with 100 digits. And 16 digits, which should be equal to
// double precision.
#ifndef MULTI_PRECISION
// TEST(BulkSphere, DISABLED_ArgPi) {
//******************************************************************************
TEST(BulkSphere, ArgPi) {
  std::vector<double> WLs{50, 80, 100, 200, 400};  // nm
  double host_index = 2.;
  double core_radius = 100.;  // nm
  double delta = 1e-5;
  nmie::MultiLayerMie<nmie::FloatType> nmie;
  nmie.SetLayersIndex({std::complex<double>(4, 0)});
  for (auto WL : WLs) {
    nmie.SetLayersSize(
        {2 * nmie::PI_ * host_index * core_radius / (WL + delta)});
    nmie.RunMieCalculation();
    double Qabs_p = std::abs(static_cast<double>(nmie.GetQabs()));

    nmie.SetLayersSize(
        {2 * nmie::PI_ * host_index * core_radius / (WL - delta)});
    nmie.RunMieCalculation();
    double Qabs_m = std::abs(static_cast<double>(nmie.GetQabs()));

    nmie.SetLayersSize({2 * nmie::PI_ * host_index * core_radius / (WL)});
    nmie.RunMieCalculation();
    double Qabs = std::abs(static_cast<double>(nmie.GetQabs()));
    EXPECT_GT(Qabs_p + Qabs_m, Qabs);
  }
}
#endif

//******************************************************************************
// A list of tests for a bulk sphere from
// Hong Du, "Mie-scattering calculation," Appl. Opt. 43, 1951-1956 (2004)
// table 1: sphere size and refractive index
// followed by resulting extinction and scattering efficiencies
std::vector<std::tuple<double, std::complex<double>, double, double, char> >
    parameters_and_results{
        // x, {Re(m), Im(m)}, Qext, Qsca, test_name
        {0.099, {0.75, 0}, 7.417859e-06, 7.417859e-06, 'a'},
        {0.101, {0.75, 0}, 8.033538e-06, 8.033538e-06, 'b'},
        {10, {0.75, 0}, 2.232265, 2.232265, 'c'},
        {100, {1.33, 1e-5}, 2.101321, 2.096594, 'e'},
        {0.055, {1.5, 1}, 0.10149104, 1.131687e-05, 'g'},
        {0.056, {1.5, 1}, 0.1033467, 1.216311e-05, 'h'},
        {100, {1.5, 1}, 2.097502, 1.283697, 'i'},
        {1, {10, 10}, 2.532993, 2.049405, 'k'},
        {1000, {0.75, 0}, 1.997908, 1.997908, 'd'},
        {100, {10, 10}, 2.071124, 1.836785, 'l'},
        {10000, {1.33, 1e-5}, 2.004089, 1.723857, 'f'},
        {10000, {1.5, 1}, 2.004368, 1.236574, 'j'},
        {10000, {10, 10}, 2.005914, 1.795393, 'm'},
    };
//******************************************************************************
TEST(BulkSphere, DISABLED_HandlesInput) {
  // TEST(BulkSphere, HandlesInput) {
  nmie::MultiLayerMie<nmie::FloatType> nmie;
  for (const auto& data : parameters_and_results) {
    auto x = std::get<0>(data);
    auto m = std::get<1>(data);
    //    auto Nstop = nmie::LeRu_near_field_cutoff(m*x)+1;
    nmie.SetLayersSize({x});
    nmie.SetLayersIndex({m});
    //    nmie.SetMaxTerms(Nstop);
    nmie.RunMieCalculation();
    double Qext = static_cast<double>(nmie.GetQext());
    double Qsca = static_cast<double>(nmie.GetQsca());
    double Qext_Du = std::get<2>(data);
    double Qsca_Du = std::get<3>(data);
    EXPECT_FLOAT_EQ(Qext_Du, Qext)
        << "Extinction of the bulk sphere, test case:" << std::get<4>(data)
        << "\nnmax_ = " << nmie.GetMaxTerms();
    EXPECT_FLOAT_EQ(Qsca_Du, Qsca)
        << "Scattering of the bulk sphere, test case:" << std::get<4>(data);
  }
}

//******************************************************************************
TEST(BulkSphere, MesoMie) {
  nmie::MultiLayerMie<nmie::FloatType> nmie;
  nmie::MesoMie<nmie::FloatType> mesomie;
  for (const auto& data : parameters_and_results) {
    auto x = std::get<0>(data);
    auto m = std::get<1>(data);
    mesomie.calc_ab(x,        // R
                    {x, 0},   // xd
                    x * m,    // xm
                    {1, 0},   // eps_d
                    m * m,    // eps_m
                    {0, 0},   // d_parallel
                    {0, 0});  // d_perp
                              // eps_m * xd / (eps_d * xm)
    mesomie.calc_Q();

    double Qext = static_cast<double>(mesomie.GetQext());
    double Qsca = static_cast<double>(mesomie.GetQsca());
    double Qext_Du = std::get<2>(data);
    double Qsca_Du = std::get<3>(data);
    EXPECT_FLOAT_EQ(Qext_Du, Qext)
        << "Extinction of the bulk sphere, test case:" << std::get<4>(data)
        << "\nnmax_ = " << nmie.GetMaxTerms();
    EXPECT_FLOAT_EQ(Qsca_Du, Qsca)
        << "Scattering of the bulk sphere, test case:" << std::get<4>(data);
  }
}
int main(int argc, char** argv) {
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}