def run_finmag(demagsolver):
"""Run the finmag simulation and store data in (demagsolvertype)averages.txt."""
sim = Sim(mesh, Ms, unit_length=unit_length)
sim.alpha = 0.5
sim.set_m((1, 0, 1))
exchange = Exchange(13.0e-12)
sim.add(exchange)
demag = Demag(solver=demagsolver)
sim.add(demag)
fh = open(os.path.join(MODULE_DIR, demagsolver + "averages.txt"), "w")
fe = open(os.path.join(MODULE_DIR, demagsolver + "energies.txt"), "w")
# Progressbar
bar = pb.ProgressBar(maxval=60, \
widgets=[pb.ETA(), pb.Bar('=', '[', ']'), ' ', pb.Percentage()])
logger.info("Time integration")
times = np.linspace(0, 3.0e-10, 61)
#times = np.linspace(0, 3.0e-10, 100000)
for counter, t in enumerate(times):
bar.update(counter)
# Integrate
sim.run_until(t)
print counter
print("press return to continue")
_ = raw_input()
# Save averages to file
mx, my, mz = sim.m_average
fh.write(str(t) + " " + str(mx) + " " + str(my) + " " + str(mz) + "\n")
# Energies
E_e = exchange.compute_energy()
E_d = demag.compute_energy()
fe.write(str(E_e) + " " + str(E_d) + "\n")
# Energy densities
if counter == 10:
exch_energy = exchange.energy_density_function()
demag_energy = demag.demag.energy_density_function()
finmag_exch, finmag_demag = [], []
R = range(100)
for i in R:
finmag_exch.append(exch_energy([15, 15, i]))
finmag_demag.append(demag_energy([15, 15, i]))
# Store data
np.save(
os.path.join(MODULE_DIR,
"finmag%s_exch_density.npy" % demagsolver),
np.array(finmag_exch))
np.save(
os.path.join(MODULE_DIR,
"finmag%s_demag_density.npy" % demagsolver),
np.array(finmag_demag))
fh.close()
fe.close()
def demag_energy():
mesh = from_geofile(os.path.join(MODULE_DIR, "sphere_fine.geo"))
S3 = df.VectorFunctionSpace(mesh, "Lagrange", 1)
m_function = df.interpolate(df.Constant((1, 0, 0)), S3)
m = Field(S3, m_function)
demag = Demag('FK')
demag.setup(m, Field(df.FunctionSpace(mesh, 'DG', 0), Ms), unit_length=1)
E = demag.compute_energy()
rel_error = abs(E - E_analytical) / abs(E_analytical)
print "Energy with FK method: {}.".format(E)
return E, rel_error
def run_finmag():
"""Run the finmag simulation and store data in averages.txt."""
sim = Sim(mesh, Ms, unit_length=unit_length)
sim.alpha = 0.5
sim.set_m((1, 0, 1))
exchange = Exchange(13.0e-12)
sim.add(exchange)
demag = Demag(solver="FK")
sim.add(demag)
fh = open(os.path.join(MODULE_DIR, "averages.txt"), "w")
fe = open(os.path.join(MODULE_DIR, "energies.txt"), "w")
logger.info("Time integration")
times = np.linspace(0, 3.0e-10, 61)
for counter, t in enumerate(times):
# Integrate
sim.run_until(t)
# Save averages to file
mx, my, mz = sim.m_average
fh.write(str(t) + " " + str(mx) + " " + str(my) + " " + str(mz) + "\n")
# Energies
E_e = exchange.compute_energy()
E_d = demag.compute_energy()
fe.write(str(E_e) + " " + str(E_d) + "\n")
# Energy densities
if counter == 10:
exch_energy = exchange.energy_density_function()
demag_energy = demag.energy_density_function()
finmag_exch, finmag_demag = [], []
R = range(100)
for i in R:
finmag_exch.append(exch_energy([15, 15, i]))
finmag_demag.append(demag_energy([15, 15, i]))
# Store data
np.save(os.path.join(MODULE_DIR, "finmag_exch_density.npy"),
np.array(finmag_exch))
np.save(os.path.join(MODULE_DIR, "finmag_demag_density.npy"),
np.array(finmag_demag))
fh.close()
fe.close()
def run_simulation(lfactor, m_init, m_init_name=""):
L = lfactor * lexch
divisions = int(round(lfactor * 2)) # that magic number influences L
mesh = df.BoxMesh(df.Point(0, 0, 0), df.Point(L, L, L), divisions,
divisions, divisions)
exchange = Exchange(A)
anisotropy = UniaxialAnisotropy(K1, [0, 0, 1])
demag = Demag()
sim = Simulation(mesh, Ms)
sim.set_m(m_init)
sim.add(exchange)
sim.add(anisotropy)
sim.add(demag)
sim.relax()
# Save average magnetisation.
mx, my, mz = sim.m_average
with open(os.path.join(MODULE_DIR, "data_m.txt"), "a") as f:
t = time.asctime()
f.write("{} {} {} {} {} {}\n".format(m_init_name, lfactor, mx, my, mz,
t))
# Save energies.
# We could call sim.total_energy, but we want the individual contributions.
e_exc = exchange.compute_energy() / (sim.Volume * Km)
e_anis = anisotropy.compute_energy() / (sim.Volume * Km)
e_demag = demag.compute_energy() / (sim.Volume * Km)
e_total = e_exc + e_anis + e_demag # relative total energy density
with open(os.path.join(MODULE_DIR, "data_energies.txt"), "a") as f:
t = time.asctime()
f.write("{} {} {} {} {} {} {}\n".format(m_init_name, lfactor, e_total,
e_exc, e_anis, e_demag, t))
return e_total
