def _scat_coeffs_internal(self, s, optics):
x_arr = optics.wavevec * _ensure_array(s.r)
m_arr = _ensure_array(s.n) / optics.index
# Check that the scatterer is in a range we can compute for
if x_arr.max() > 1e3:
raise UnrealizableScatterer(self, s, "radius too large, field "+
"calculation would take forever")
if len(x_arr) == 1 and len(m_arr) == 1:
# Could just use scatcoeffs_multi here, but jerome is in favor of
# keeping the simpler single layer code here
lmax = miescatlib.nstop(x_arr[0])
return miescatlib.internal_coeffs(m_arr[0], x_arr[0], lmax)
def _scat_coeffs_internal(self, s, optics):
x_arr = optics.wavevec * _ensure_array(s.r)
m_arr = _ensure_array(s.n) / optics.index
# Check that the scatterer is in a range we can compute for
if x_arr.max() > 1e3:
raise UnrealizableScatterer(
self, s,
"radius too large, field " + "calculation would take forever")
if len(x_arr) == 1 and len(m_arr) == 1:
# Could just use scatcoeffs_multi here, but jerome is in favor of
# keeping the simpler single layer code here
lmax = miescatlib.nstop(x_arr[0])
return miescatlib.internal_coeffs(m_arr[0], x_arr[0], lmax)
def test_mie_internal_coeffs():
if os.name == 'nt':
raise SkipTest()
m = 1.5 + 0.1j
x = 50.
n_stop = miescatlib.nstop(x)
al, bl = miescatlib.scatcoeffs(m, x, n_stop)
cl, dl = miescatlib.internal_coeffs(m, x, n_stop)
n = np.arange(n_stop)+1
jlx = spherical_jn(n, x)
jlmx = spherical_jn(n, m*x)
hlx = jlx + 1.j * spherical_yn(n, x)
assert_allclose(cl, (jlx - hlx * bl) / jlmx, rtol = 1e-6, atol = 1e-6)
assert_allclose(dl, (jlx - hlx * al)/ (m * jlmx), rtol = 1e-6, atol = 1e-6)
def _scat_coeffs_internal(self, s, medium_wavevec, medium_index):
'''
Calculate expansion coefficients for Lorenz-Mie electric field
inside a sphere.
'''
x_arr = medium_wavevec * ensure_array(s.r)
m_arr = ensure_array(s.n) / medium_index
# Check that the scatterer is in a range we can compute for
if x_arr.max() > 1e3:
msg = "radius too large, field calculation would take forever"
raise InvalidScatterer(s, msg)
if len(x_arr) == 1 and len(m_arr) == 1:
# Could just use scatcoeffs_multi here, but jerome is in favor of
# keeping the simpler single layer code here
lmax = miescatlib.nstop(x_arr[0])
return miescatlib.internal_coeffs(m_arr[0], x_arr[0], lmax)
def test_mie_bndy_conds():
'''
Check that appropriate boundary conditions are satisfied:
m^2 E_radial continuous (bound charge Gaussian pillbox)
E_parallel continuous (Amperian loop)
Checks to do (all on E_x):
theta = 0, phi = 0 (theta component)
theta = 90, phi = 0 (radial component)
theta = 90, phi = 90 (phi component)
'''
m = 1.2 + 0.01j
x = 10.
pol = np.array([1., 0.]) # assume x polarization
n_stop = miescatlib.nstop(x)
asbs = miescatlib.scatcoeffs(m, x, n_stop)
csds = miescatlib.internal_coeffs(m, x, n_stop)
# define field points
eps = 1e-6 # get just inside/outside boundary
kr_ext = np.ones(3) * (x + eps)
kr_int = np.ones(3) * (x - eps)
thetas = np.array([0., pi/2., pi/2.])
phis = np.array([0., 0., pi/2.])
points_int = np.vstack((kr_int, thetas, phis))
points_ext = np.vstack((kr_ext, thetas, phis))
# calc escat
es_x, es_y, es_z = mieangfuncs.mie_fields(points_ext, asbs, pol, 1, 1)
# calc eint
eint_x, eint_y, eint_z = mieangfuncs.mie_internal_fields(points_int, m,
csds, pol)
# theta check
assert_allclose(eint_x[0], es_x[0] + exp(1.j * (x + eps)), rtol = 5e-6)
# r check
assert_allclose(m**2 * eint_x[1], es_x[1] + 1., rtol = 5e-6)
# phi check
assert_allclose(eint_x[2], es_x[2] + 1., rtol = 5e-6)