def test_anisotropy_field_supported_methods(fixt):
"""
Check that all supported methods give the same results as the default method.
"""
TOLERANCE = 1e-13
fixt["m"].set(df.Constant((1 / np.sqrt(2), 0, 1 / np.sqrt(2))))
H_default = fixt["anis"].compute_field()
supported_methods = list(UniaxialAnisotropy._supported_methods)
# No need to compare default method with itself.
supported_methods.remove(fixt["anis"].method)
for method in supported_methods:
anis = UniaxialAnisotropy(fixt["K1"], fixt["a"], method=method)
anis.setup(fixt["m"], fixt["Ms"])
H = anis.compute_field()
print(
textwrap.dedent("""
With method '{}',
expecting: H = {},
got: H = {}.
""".format(method,
H_default.reshape((3, -1)).mean(axis=1),
H.reshape((3, -1)).mean(axis=1))))
assert np.allclose(H, H_default, atol=0, rtol=TOLERANCE)
def compute_finmag_anis(m_gen, Ms, K1, axis, dolfin_mesh):
S3 = df.VectorFunctionSpace(dolfin_mesh, "Lagrange", 1, dim=3)
coords = np.array(zip(*dolfin_mesh.coordinates()))
m0 = m_gen(coords).flatten()
m = Field(S3)
m.set_with_numpy_array_debug(m0)
anis = UniaxialAnisotropy(K1, axis)
anis.setup(m, Field(df.FunctionSpace(dolfin_mesh, 'DG', 0), Ms))
anis_field = df.Function(S3)
anis_field.vector()[:] = anis.compute_field()
return anis_field
def setup_module(module=None):
x_max = 100e-9 # m
simplexes = 50
mesh = dolfin.IntervalMesh(simplexes, 0, x_max)
def m_gen(coords):
x = coords[0]
mx = min(1.0, x / x_max)
mz = 0.1
my = np.sqrt(1.0 - (0.99 * mx**2 + mz**2))
return np.array([mx, my, mz])
K1 = 520e3 # J/m^3
Ms = 0.86e6
sim = Sim(mesh, Ms)
sim.alpha = 0.2
sim.set_m(m_gen)
anis = UniaxialAnisotropy(K1, (0, 0, 1))
sim.add(anis)
# Save H_anis and m at t0 for comparison with nmag
global H_anis_t0, m_t0
H_anis_t0 = anis.compute_field()
m_t0 = sim.m
av_f = open(os.path.join(MODULE_DIR, "averages.txt"), "w")
tn_f = open(os.path.join(MODULE_DIR, "third_node.txt"), "w")
t = 0
t_max = 3e-10
dt = 5e-12
# s
while t <= t_max:
mx, my, mz = sim.m_average
averages.append([t, mx, my, mz])
av_f.write(
str(t) + " " + str(mx) + " " + str(my) + " " + str(mz) + "\n")
mx, my, mz = h.components(sim.m)
m2x, m2y, m2z = mx[2], my[2], mz[2]
third_node.append([t, m2x, m2y, m2z])
tn_f.write(
str(t) + " " + str(m2x) + " " + str(m2y) + " " + str(m2z) + "\n")
t += dt
sim.run_until(t)
av_f.close()
tn_f.close()
def setup(K2=K2):
print "Running finmag..."
mesh = from_geofile(os.path.join(MODULE_DIR, "bar.geo"))
coords = np.array(zip(*mesh.coordinates()))
S3 = df.VectorFunctionSpace(mesh, "Lagrange", 1, dim=3)
m = Field(S3)
m.set_with_numpy_array_debug(m_gen(coords).flatten())
S1 = df.FunctionSpace(mesh, "Lagrange", 1)
Ms_cg = Field(df.FunctionSpace(mesh, 'CG', 1), Ms)
anisotropy = UniaxialAnisotropy(K1, u1, K2=K2)
anisotropy.setup(m, Ms_cg, unit_length=1e-9)
H_anis = df.Function(S3)
H_anis.vector()[:] = anisotropy.compute_field()
return dict(m=m, H=H_anis, S3=S3, table=start_table())