def compute(M, Ms, A, rotations=1):
for _ in range(rotations):
M = right_rotate_vector_field(M)
Ms = right_rotate_field(Ms); A = right_rotate_field(A)
H = VectorField(M.mesh)
nx, ny, nz = M.mesh.num_nodes
dx, dy, dz = M.mesh.delta
pbc, pbc_rep = M.mesh.periodic_bc
bcx, bcy, bcz = "x" in pbc, "y" in pbc, "z" in pbc
magneto.fdm_exchange(nx, ny, nz, dx, dy, dz, bcx, bcy, bcz, Ms, A, M, H)
for _ in range(rotations): H = left_rotate_vector_field(H)
return H
def pbc_exchange(self, nx, ny, nz):
dx, dy, dz = 1e-9, 1e-9, 1e-9
mesh = RectangularMesh((nx, ny, nz), (dx, dy, dz))
A = Field(mesh); A.fill(Material.Py().A)
Ms = Field(mesh); Ms.fill(Material.Py().Ms)
M = VectorField(mesh)
H = VectorField(mesh)
for bcx, bcy, bcz in itertools.product([False, True], [False, True], [False, True]):
M.fill(tuple((random.random()-0.5) * 2e5 for i in range(3)))
#M.fill((8e5, 8e5, -8e5))
magneto.fdm_exchange(nx, ny, nz, dx, dy, dz, bcx, bcy, bcz, Ms, A, M, H)
for i in range(nx*ny*nz):
self.assertEquals(H.get(i), (0.0, 0.0, 0.0))
def do_test(self, M_file, H_file, epsilon):
# load ref
M = readOMF(M_file)
H_ref = readOMF(H_file)
H = VectorField(M.mesh)
A = Field(M.mesh); A.fill(Material.Py().A)
Ms = Field(M.mesh); Ms.fill(Material.Py().Ms)
# calculate
mesh = M.mesh
nx, ny, nz = mesh.num_nodes
dx, dy, dz = mesh.delta
bcx, bcy, bcz = False, False, False
magneto.fdm_exchange(nx, ny, nz, dx, dy, dz, bcx, bcy, bcz, Ms, A, M, H)
# compare
self.assertVectorFieldEqual(H_ref, H, epsilon)
def calculate(self, state, id):
cache = state.cache
if id == "H_exch":
if hasattr(cache, "H_exch"): return cache.H_exch
H_exch = cache.H_exch = VectorField(self.system.mesh)
nx, ny, nz = self.system.mesh.num_nodes
dx, dy, dz = self.system.mesh.delta
bcx, bcy, bcz = self.__peri_x, self.__peri_y, self.__peri_z
magneto.fdm_exchange(nx, ny, nz, dx, dy, dz, bcx, bcy, bcz, self.system.Ms, self.system.A, state.M, H_exch)
return H_exch
elif id == "E_exch":
return -MU0/2.0 * self.system.mesh.cell_volume * state.M.dotSum(state.H_exch)
else:
raise KeyError("ExchangeField.calculate: Can't calculate %s", id)
