Constant excitation coefficient problem

Former-commit-id: a20f0ea21796c5aa11a3084927a08e885085b610
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Marek Nečada 2016-09-19 01:32:44 +03:00
parent bd0e7e7257
commit 72b0c96d49
1 changed files with 179 additions and 0 deletions

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@ -1349,3 +1349,182 @@ def scatter_plane_wave_rectarray(omega, epsilon_b, xN, yN, xd, yd, TMatrices, k_
returnlist.append(x) returnlist.append(x)
returnlist.append(y) returnlist.append(y)
return tuple(returnlist) return tuple(returnlist)
import warnings
def scatter_constmultipole_rectarray(omega, epsilon_b, xN, yN, xd, yd, TMatrices, pq_0_c = 1,
return_pq= False, return_xy = False, watch_time = False):
"""
Solves the plane wave linear scattering problem for a rectangular array of particles
for one frequency and constant exciting spherical waves throughout the array.
Parameters
----------
omega : positive number
The frequency of the field.
epsilon_b : complex number
Permittivity of the background medium (which has to be isotropic).
xN, yN : positive integers
Particle numbers in the x and y dimensions
xd, yd : positive numbers
Periodicities in the x and y direction
TMatrices : (xN, yN,2,nelem,2,nelem) or compatible or (2,nelem,2,nelem)
The T-matrices in the "Taylor convention" describing the scattering on a single nanoparticle.
If all the particles are identical and equally oriented, only one T-matrix can be given.
nelems = (lMax + 2) * lMax, where lMax is the highest multipole order to which the scattering
is calculated.
Electric wave index is 0, magnetic wave index is 1.
pq_0_c : (nelem)-shaped complex array or compatible
The initial excitation coefficients for the ("complex") multipole waves, in Taylor's convention.
return_pq : bool NOT IMPLEMENTED
Return also the multipole decomposition coefficients of the field incoming to each
particle (inc. the field scattered from other particles.
return_xy : bool
Return also the cartesian x, y positions of the particles.
watch_time : bool
Inform about the progress on stderr
Returns
-------
ab : (nelem, xN, yN, 2, nelem)-shaped complex array
The a (electric wave), b (magnetic wave) coefficients of the outgoing field for each particle.
If none of return_pq or return_xy is set, the array is not enclosed in a tuple.
pq : (nelem, xN, yN, 2, nelem)-shaped complex array NOT IMPLEMENTED
The p (electric wave), q (magnetic wave) coefficients of the total exciting field
for each particle (including the field scattered from other particles)
x, y : (xN, yN)-shaped real array
The x,y positions of the nanoparticles.
"""
if (watch_time):
timec = time.time()
print('%.4f: running scatter_plane_wave_rectarray' % timec, file = sys.stderr)
sys.stderr.flush()
nelem = TMatrices.shape[-1]
if ((nelem != TMatrices.shape[-3]) or (2 != TMatrices.shape[-2]) or (2 != TMatrices.shape[-4])):
raise ValueError('The T-matrices must be of shape (N, 2, nelem, 2, nelem) but are of shape %s' % (str(TMatrices.shape),))
lMax = nelem2lMax(nelem)
if not lMax:
raise ValueError('The "nelem" dimension of T-matrix has invalid value (%d).' % nelem)
if (watch_time):
print('xN = %d, yN = %d, lMax = %d' % (xN, yN, lMax), file = sys.stderr)
sys.stderr.flush()
# TODO perhaps more checks.
k_out = omega * math.sqrt(epsilon_b) / c # wave number
my, ny = get_mn_y(lMax)
N = yN * xN
J_scat=3
J_ext=1
# Do something with this ugly indexing crap
xind, yind = np.meshgrid(np.arange(xN),np.arange(yN), indexing='ij')
xind = xind.flatten()
yind = yind.flatten()
xyind = np.stack((xind, yind, np.zeros((xind.shape),dtype=int)),axis=-1)
cart_lattice=xyind * np.array([xd, yd, 0])
x=cart_lattice[:,0]
y=cart_lattice[:,1]
xyind = xyind[:,0:2]
# Lattice speedup
if (watch_time):
timec = time.time()
print('%.4f: calculating the %d translation matrix elements' % (timec, 8*nelem*nelem*xN*yN), file = sys.stderr)
sys.stderr.flush()
Agrid = np.zeros((nelem, 2*xN, 2*yN, nelem),dtype=np.complex_)
Bgrid = np.zeros((nelem, 2*xN, 2*yN, nelem),dtype=np.complex_)
for yl in range(nelem): # source
for xij in range(2*xN):
for yij in range(2*yN):
for yj in range(nelem): #dest
if((yij != yN) or (xij != xN)):
d_l2j = cart2sph(np.array([(xij-xN)*xd, (yij-yN)*yd, 0]))
Agrid[yj, xij, yij, yl] = Ã(my[yj],ny[yj],my[yl],ny[yl],kdlj=d_l2j[0]*k_out,θlj=d_l2j[1],φlj=d_l2j[2],r_ge_d=False,J=J_scat)
Bgrid[yj, xij, yij, yl] = B̃(my[yj],ny[yj],my[yl],ny[yl],kdlj=d_l2j[0]*k_out,θlj=d_l2j[1],φlj=d_l2j[2],r_ge_d=False,J=J_scat)
# Translation coefficient matrix T
if (watch_time):
timecold = timec
timec = time.time()
print('%4f: translation matrix elements calculated (elapsed %.2f s), filling the matrix'
% (timec, timec-timecold), file = sys.stderr)
sys.stderr.flush()
transmat = np.zeros((xN* yN, 2, nelem, xN* yN, 2, nelem),dtype=np.complex_)
for l in range(N):
xil, yil = xyind[l]
for j in range(N):
xij, yij = xyind[j]
if (l!=j):
transmat[j,0,:,l,0,:] = Agrid[:, xij - xil + xN, yij - yil + yN, :]
transmat[j,0,:,l,1,:] = Bgrid[:, xij - xil + xN, yij - yil + yN, :]
transmat[j,1,:,l,0,:] = Bgrid[:, xij - xil + xN, yij - yil + yN, :]
transmat[j,1,:,l,1,:] = Agrid[:, xij - xil + xN, yij - yil + yN, :]
Agrid = None
Bgrid = None
if (watch_time):
timecold = timec
timec = time.time()
print('%4f: translation matrix filled (elapsed %.2f s), building the interaction matrix'
% (timec, timec-timecold), file=sys.stderr)
sys.stderr.flush()
# Now we solve a linear problem (1 - M T) A = M P_0 where M is the T-matrix :-)
MT = np.empty((N,2,nelem,N,2,nelem),dtype=np.complex_)
TMatrices = np.broadcast_to(TMatrices, (xN, yN, 2, nelem, 2, nelem))
for j in range(N): # I wonder how this can be done without this loop...
xij, yij = xyind[j]
MT[j] = np.tensordot(TMatrices[xij, yij],transmat[j],axes=([-2,-1],[0,1]))
MT.shape = (N*2*nelem, N*2*nelem)
leftmatrix = np.identity(N*2*nelem) - MT
MT = None
if (watch_time):
timecold = timec
timec = time.time()
print('%.4f: interaction matrix complete (elapsed %.2f s)' % (timec, timec-timecold),
file=sys.stderr)
sys.stderr.flush()
# А ну, чики-брики и в дамки!
if watch_time:
timecold = time.time()
print('%.4f: factorizing the interaction matrix' % timecold, file=sys.stderr)
sys.stderr.flush()
lupiv = scipy.linalg.lu_factor(leftmatrix, overwrite_a=True)
leftmatrix = None
if watch_time:
timec = time.time()
print('%.4f: factorization complete (elapsed %.2f s)' % (timec, timec-timecold),
file = sys.stderr)
print('%.4f: solving the scattering problem for %d incoming waves' % (timec, K),
file=sys.stderr)
sys.stderr.flush()
timecold = timec
ab = np.empty((2,nelem,N*2*nelem), dtype=complex)
for N_or_M in range(2):
for yy in range(nelem):
pq_0 = np.zeros((2,nelem), dtype=np.complex_)
pq_0[N_or_M,yy] = pq_0_c[N_or_M,yy]
pq_0 = broadcast_to(pq_0, (N, 2, nelem))
MP_0 = np.empty((N,2,nelem),dtype=np.complex_)
for j in range(N): # I wonder how this can be done without this loop...
MP_0[j] = np.tensordot(TMatrices[xij, yij],pq_0[j],axes=([-2,-1],[-2,-1]))
MP_0.shape = (N*2*nelem,)
ab[N_or_M, yy] = scipy.linalg.lu_solve(lupiv, MP_0)
ab.shape = (nelem, xN, yN, 2, nelem)
if watch_time:
timec = time.time()
print('%.4f: done (elapsed %.2f s)' % (timec, timec-timecold),file = sys.stderr)
sys.stderr.flush()
if not (return_pq_0 + return_pq + return_xy):
return ab
returnlist = [ab]
if (return_pq):
warnings.warn("return_pq not implemented, ignoring")
# returnlist.append(pq_arr)
if (return_xy):
returnlist.append(x)
returnlist.append(y)
return tuple(returnlist)