Function freq_at_resolution

tests/2D_convergence.cpp:42–65

}

double freq_at_resolution(double e(const vec &), double a, component c, double beta) {
  const grid_volume gv = vol2d(2.0, 1.0, a);
  structure s(gv, e);
  s.set_epsilon(e);

  fields f(&s, 0, beta);
  f.use_real_fields();
  f.use_bloch(vec(0, 0));
  f.add_point_source(c, 0.18, 2.5, 0.0, 6.0, vec(0.5, 0.5), 1.0);
  f.add_point_source(c, 0.18, 2.5, 0.0, 6.0, vec(1.5, 0.5), -1.0);

  while (f.time() <= f.last_source_time() + 10.0)
    f.step();
  const double fourier_timesteps = 3000.0;
  const double ttot = fourier_timesteps / a + f.time();
  monitor_point *p = NULL;
  while (f.time() <= ttot) {
    f.step();
    p = f.get_new_point(vec(0.52, 0.97), p);
  }
  const double freq = get_the_freq(p, c);
  delete p;
  return freq;
}

void check_convergence(component c, double best_guess, double beta) {
  const double amin = 5.0, amax = 30.0, adelta = 5.0;