Ewald summation consistency test for lattice basis fields.

In-plane test currently passes, out-of-plane does not.

tests/test_ewald_consistency.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+'''
+Test 2D Ewald summation consistency for basis VSWFs, using varying values of eta.
+'''
+import sys
+# Test parameters, rather arbitrary
+
+npoints = 10
+
+etafactors = [0.9, 1.1]
+
+zpointmax = 0. if len(sys.argv) == 1 else float(sys.argv[1])
+lattice_basis=[(580e-9,0),(0,580e-9)]
+positions = [(0,0)] # particle positions
+wavevector = [0.,0.,0.]
+bgparam = 1.52
+omega_eh = 2.1
+lMax = 2
+
+
+import numpy as np
+from qpms import Particle, CTMatrix, lorentz_drude, EpsMuGenerator, TMatrixGenerator, EwaldPart, BaseSpec, FinitePointGroup, ScatteringSystem, TMatrixInterpolator, EpsMu, dbgmsg_enable, dbgmsg_disable, dbgmsg_active, BesselType,eV, hbar, c
+from qpms.symmetries import point_group_info
+eh = eV/hbar
+np.random.seed(666)
+
+omega = omega_eh * eh
+
+bspec = BaseSpec(lMax=lMax)
+medium = EpsMuGenerator(bgparam)
+emg_dummy = EpsMuGenerator(10)
+tmg_dummy = TMatrixGenerator.sphere(medium, emg_dummy, 50e-9)
+
+particles = [Particle(pos, tmg_dummy, bspec) for pos in positions]
+
+ss, ssw = ScatteringSystem.create(particles, medium, omega, latticebasis=lattice_basis)
+wavevector = np.array(wavevector)
+
+sswk = ssw._sswk(wavevector)
+eta_orig = sswk.eta
+
+print("default eta: %g" % (eta_orig,))
+print("lattice basis:\n", ss.lattice_basis)
+
+points =  (np.random.rand(npoints) - .5)[:,None] * ss.lattice_basis[0] + (np.random.rand(npoints) - .5)[:,None] * ss.lattice_basis[1]
+points += (np.random.rand(npoints) - .5)[:,None] * np.array([0.,0.,zpointmax])
+
+
+fields_reference = sswk.scattered_field_basis(points)
+
+fields = np.empty((len(etafactors),) + fields_reference.shape, dtype=complex)
+
+fails = 0
+
+for n, etafactor in enumerate(etafactors):
+    sswk.eta = eta_orig * etafactor
+    fields[n] = sswk.scattered_field_basis(points)
+    print(fields[n])
+    print(fields[n]-fields_reference)
+    if np.sum(1-np.isclose(fields[n], fields_reference)) > 0: 
+        fails += 1
+
+print(fails)
+
+sys.exit(int(fails))