def test_step_integrator(integrator, stepsize_reported, stepsize_internal):
ts = np.arange(interval[0], interval[1], step=stepsize_reported)
print(ts)
print(ts[1:])
ys = np.zeros(ts.shape[0])
ys[0] = y_true(ts[0]) # known initial value
integrator = StepIntegrator(ys[0],
f,
step="euler",
stepsize=stepsize_internal)
for i, t in enumerate(ts[1:]):
integrator.run_until(t)
ts[i + 1] = integrator.t
ys[i + 1] = integrator.y
assert 85 < ys[-1] < 100
return ts, ys
def set_integrator(self, integrator, use_jac):
# Integrator options --------------------------------------------------
# Here we set up the CVODE integrator from Sundials to evolve a
# specific micromagnetic equation. The equations are specified in the
# sundials_rhs function from any of the micromagnetic drivers in the
# micromagnetic folder (LLG, LLG_STT, etc.)
if integrator == "sundials" and use_jac:
self.integrator = CvodeSolver(self.spin, self.sundials_rhs,
self.sundials_jtimes)
elif integrator == "sundials_diag":
self.integrator = CvodeSolver(self.spin,
self.sundials_rhs,
linear_solver="diag")
elif integrator == "sundials":
self.integrator = CvodeSolver(self.spin, self.sundials_rhs)
elif integrator == "euler" or integrator == "rk4":
self.integrator = StepIntegrator(self.spin, self.step_rhs)
elif integrator == "scipy":
self.integrator = ScipyIntegrator(self.spin, self.step_rhs)
elif integrator == "sundials_openmp" and use_jac:
self.integrator = CvodeSolver_OpenMP(self.spin, self.sundials_rhs,
self.sundials_jtimes)
elif integrator == "sundials_diag_openmp":
self.integrator = CvodeSolver_OpenMP(self.spin,
self.sundials_rhs,
linear_solver="diag")
elif integrator == "sundials_openmp":
self.integrator = CvodeSolver_OpenMP(self.spin, self.sundials_rhs)
elif integrator == "euler_openmp" or integrator == "rk4_openmp":
self.integrator = CvodeSolver_OpenMP(self.spin, self.step_rhs,
integrator)
else:
raise NotImplemented("integrator must be sundials, euler or rk4")
def __init__(self, mesh, name='unnamed', integrator='sundials'):
"""Simulation object.
*Arguments*
name : the Simulation name (used for writing data files, for examples)
"""
self.t = 0
self.name = name
self.mesh = mesh
self.n = mesh.n
self.n_nonzero = mesh.n
self.unit_length = mesh.unit_length
self._alpha = np.zeros(self.n, dtype=np.float)
self._Ms = np.zeros(self.n, dtype=np.float)
self._Ms_inv = np.zeros(self.n, dtype=np.float)
self.spin = np.ones(3 * self.n, dtype=np.float)
self.spin_last = np.ones(3 * self.n, dtype=np.float)
self._pins = np.zeros(self.n, dtype=np.int32)
self.field = np.zeros(3 * self.n, dtype=np.float)
self.dm_dt = np.zeros(3 * self.n, dtype=np.float)
self._skx_number = np.zeros(self.n, dtype=np.float)
self.interactions = []
self.pin_fun = None
self.integrator_tolerances_set = False
self.step = 0
if integrator == "sundials":
self.integrator = SundialsIntegrator(self.spin, self.sundials_rhs)
elif integrator == "euler" or integrator == "rk4":
self.integrator = StepIntegrator(self.spin, self.step_rhs, integrator)
else:
raise NotImplemented("integrator must be sundials, euler or rk4")
self.saver = DataSaver(self, name + '.txt')
self.saver.entities['E_total'] = {
'unit': '<J>',
'get': lambda sim: sim.compute_energy(),
'header': 'E_total'}
self.saver.entities['m_error'] = {
'unit': '<>',
'get': lambda sim: sim.compute_spin_error(),
'header': 'm_error'}
self.saver.entities['skx_num'] = {
'unit': '<>',
'get': lambda sim: sim.skyrmion_number(),
'header': 'skx_num'}
self.saver.entities['rhs_evals'] = {
'unit': '<>',
'get': lambda sim: self.integrator.rhs_evals,
'header': 'rhs_evals'}
self.saver.entities['real_time'] = {
'unit': '<s>',
'get': lambda _: time.time(), # seconds since epoch
'header': 'real_time'}
self.saver.update_entity_order()
# This is for old C files codes using the xperiodic variables
self.xperiodic, self.yperiodic, self.zperiodic = mesh.periodicity
self.vtk = SaveVTK(self.mesh, name=name)
self.set_default_options()
class LLG(object):
def __init__(self, mesh, name='unnamed', integrator='sundials'):
"""Simulation object.
*Arguments*
name : the Simulation name (used for writing data files, for examples)
"""
self.t = 0
self.name = name
self.mesh = mesh
self.n = mesh.n
self.n_nonzero = mesh.n
self.unit_length = mesh.unit_length
self._alpha = np.zeros(self.n, dtype=np.float)
self._Ms = np.zeros(self.n, dtype=np.float)
self._Ms_inv = np.zeros(self.n, dtype=np.float)
self.spin = np.ones(3 * self.n, dtype=np.float)
self.spin_last = np.ones(3 * self.n, dtype=np.float)
self._pins = np.zeros(self.n, dtype=np.int32)
self.field = np.zeros(3 * self.n, dtype=np.float)
self.dm_dt = np.zeros(3 * self.n, dtype=np.float)
self._skx_number = np.zeros(self.n, dtype=np.float)
self.interactions = []
self.pin_fun = None
self.integrator_tolerances_set = False
self.step = 0
if integrator == "sundials":
self.integrator = SundialsIntegrator(self.spin, self.sundials_rhs)
elif integrator == "euler" or integrator == "rk4":
self.integrator = StepIntegrator(self.spin, self.step_rhs, integrator)
else:
raise NotImplemented("integrator must be sundials, euler or rk4")
self.saver = DataSaver(self, name + '.txt')
self.saver.entities['E_total'] = {
'unit': '<J>',
'get': lambda sim: sim.compute_energy(),
'header': 'E_total'}
self.saver.entities['m_error'] = {
'unit': '<>',
'get': lambda sim: sim.compute_spin_error(),
'header': 'm_error'}
self.saver.entities['skx_num'] = {
'unit': '<>',
'get': lambda sim: sim.skyrmion_number(),
'header': 'skx_num'}
self.saver.entities['rhs_evals'] = {
'unit': '<>',
'get': lambda sim: self.integrator.rhs_evals,
'header': 'rhs_evals'}
self.saver.entities['real_time'] = {
'unit': '<s>',
'get': lambda _: time.time(), # seconds since epoch
'header': 'real_time'}
self.saver.update_entity_order()
# This is for old C files codes using the xperiodic variables
self.xperiodic, self.yperiodic, self.zperiodic = mesh.periodicity
self.vtk = SaveVTK(self.mesh, name=name)
self.set_default_options()
def set_default_options(self, gamma=2.21e5, Ms=8.0e5, alpha=0.1):
self.default_c = 1e11
self._alpha[:] = alpha
self._Ms[:] = Ms
self.gamma = gamma
self.do_procession = True
def reset_integrator(self, t=0):
self.integrator.reset(self.spin, t)
self.t = t # also reinitialise the simulation time and step
self.step = 0
def set_tols(self, rtol=1e-8, atol=1e-10, max_ord=None, reset=True):
if max_ord is not None:
self.integrator.set_tols(rtol=rtol, atol=atol, max_ord=max_ord)
else:
# not all integrators have max_ord (only VODE does)
# and we don't want to encode a default value here either
self.integrator.set_tols(rtol=rtol, atol=atol)
if reset:
self.reset_integrator(self.t)
def set_m(self, m0=(1, 0, 0), normalise=True):
self.spin[:] = helper.init_vector(m0, self.mesh, normalise)
# TODO: carefully checking and requires to call set_mu first
self.spin.shape = (-1, 3)
for i in range(self.spin.shape[0]):
if self._Ms[i] == 0:
self.spin[i, :] = 0
self.spin.shape = (-1,)
self.integrator.set_initial_value(self.spin, self.t)
def get_pins(self):
return self._pins
def set_pins(self, pin):
self._pins[:] = helper.init_scalar(pin, self.mesh)
for i in range(len(self._Ms)):
if self._Ms[i] == 0.0:
self._pins[i] = 1
pins = property(get_pins, set_pins)
def get_alpha(self):
return self._alpha
def set_alpha(self, value):
self._alpha[:] = helper.init_scalar(value, self.mesh)
alpha = property(get_alpha, set_alpha)
def get_Ms(self):
return self._Ms
def set_Ms(self, value):
self._Ms[:] = helper.init_scalar(value, self.mesh)
nonzero = 0
for i in range(self.n):
if self._Ms[i] > 0.0:
self._Ms_inv = 1.0 / self._Ms[i]
nonzero += 1
self.n_nonzero = nonzero
for i in range(len(self._Ms)):
if self._Ms[i] == 0.0:
self._pins[i] = 1
self.Ms_const = np.max(self._Ms)
Ms = property(get_Ms, set_Ms)
def add(self, interaction, save_field=False):
interaction.setup(self.mesh, self.spin, Ms=self._Ms)
# TODO: FIX
for i in self.interactions:
if i.name == interaction.name:
interaction.name = i.name + '_2'
self.interactions.append(interaction)
energy_name = 'E_{0}'.format(interaction.name)
self.saver.entities[energy_name] = {
'unit': '<J>',
'get': lambda sim: sim.get_interaction(interaction.name).compute_energy(),
'header': energy_name}
if save_field:
fn = '{0}'.format(interaction.name)
self.saver.entities[fn] = {
'unit': '<>',
'get': lambda sim: sim.get_interaction(interaction.name).average_field(),
'header': ('%s_x' % fn, '%s_y' % fn, '%s_z' % fn)}
self.saver.update_entity_order()
def get_interaction(self, name):
for interaction in self.interactions:
if interaction.name == name:
return interaction
else:
raise ValueError("Failed to find the interaction with name '{0}', "
"available interactions: {1}.".format(
name, [x.name for x in self.interactions]))
def run_until(self, t):
if t <= self.t:
if t == self.t and self.t == 0.0:
self.compute_effective_field(t)
self.saver.save()
return
self.spin_last[:] = self.spin[:]
flag = self.integrator.run_until(t)
if flag < 0:
raise Exception("Run cython run_until failed!!!")
self.spin[:] = self.integrator.y[:]
self.t = t
self.step += 1
self.compute_effective_field(t) # update fields before saving data
self.saver.save()
def compute_effective_field(self, t):
#self.spin[:] = y[:]
self.field[:] = 0
for obj in self.interactions:
self.field += obj.compute_field(t)
def sundials_rhs(self, t, y, ydot):
self.t = t
# already synchronized when call this funciton
# self.spin[:]=y[:]
self.compute_effective_field(t)
clib.compute_llg_rhs(ydot,
self.spin,
self.field,
self.alpha,
self._pins,
self.gamma,
self.n,
self.do_procession,
self.default_c)
#ydot[:] = self.dm_dt[:]
return 0
def step_rhs(self, t, y):
self.t = t
self.compute_effective_field(t)
clib.compute_llg_rhs(self.dm_dt,
self.spin,
self.field,
self.alpha,
self._pins,
self.gamma,
self.n,
self.do_procession,
self.default_c)
return self.dm_dt
def compute_average(self):
self.spin.shape = (-1, 3)
average = np.sum(self.spin, axis=0) / self.n_nonzero
self.spin.shape = (3 * self.n)
return average
def compute_energy(self):
energy = 0
for obj in self.interactions:
energy += obj.compute_energy()
return energy
def skyrmion_number(self):
nx = self.mesh.nx
ny = self.mesh.ny
nz = self.mesh.nz
number = clib.compute_skymrion_number(
self.spin, self._skx_number, nx, ny, nz, self.mesh.neighbours)
return number
def spin_at(self, i, j, k):
i1 = 3 * self.mesh.index(i, j, k)
# print self.spin.shape,nxy,nx,i1,i2,i3
return np.array([self.spin[i1],
self.spin[i1 + 1],
self.spin[i1 + 2]])
def add_monitor_at(self, i, j, k, name='p'):
"""
Save site spin with index (i,j,k) to txt file.
"""
self.saver.entities[name] = {
'unit': '<>',
'get': lambda sim: sim.spin_at(i, j, k),
'header': (name + '_x', name + '_y', name + '_z')}
self.saver.update_entity_order()
def save_vtk(self):
self.vtk.save_vtk(self.spin.reshape(-1, 3), self.Ms, step=self.step)
def save_m(self):
if not os.path.exists('%s_npys' % self.name):
os.makedirs('%s_npys' % self.name)
name = '%s_npys/m_%g.npy' % (self.name, self.step)
np.save(name, self.spin)
def save_skx(self):
if not os.path.exists('%s_skx_npys' % self.name):
os.makedirs('%s_skx_npys' % self.name)
name = '%s_skx_npys/m_%g.npy' % (self.name, self.step)
np.save(name, self._skx_number)
def stat(self):
return self.integrator.stat()
def spin_length(self):
self.spin.shape = (3, -1)
length = np.sqrt(np.sum(self.spin**2, axis=0))
self.spin.shape = (-1,)
return length
def compute_spin_error(self):
length = self.spin_length() - 1.0
length[self._pins > 0] = 0
return np.max(abs(length))
def compute_dmdt(self, dt):
m0 = self.spin_last
m1 = self.spin
dm = (m1 - m0).reshape((3, -1))
max_dm = np.max(np.sqrt(np.sum(dm**2, axis=0)))
max_dmdt = max_dm / dt
return max_dmdt
def relax(self, dt=1e-11, stopping_dmdt=0.01, max_steps=1000,
save_m_steps=100, save_vtk_steps=100):
ONE_DEGREE_PER_NS = 17453292.52
for i in range(0, max_steps + 1):
cvode_dt = self.integrator.get_current_step()
increment_dt = dt
if cvode_dt > dt:
increment_dt = cvode_dt
self.run_until(self.t + increment_dt)
if save_vtk_steps is not None:
if i % save_vtk_steps == 0:
self.save_vtk()
if save_m_steps is not None:
if i % save_m_steps == 0:
self.save_m()
dmdt = self.compute_dmdt(increment_dt)
print 'step=%d, time=%g, max_dmdt=%g ode_step=%g' % (self.step,
self.t,
dmdt / ONE_DEGREE_PER_NS,
cvode_dt)
if dmdt < stopping_dmdt * ONE_DEGREE_PER_NS:
break
if save_m_steps is not None:
self.save_m()
if save_vtk_steps is not None:
self.save_vtk()
def __init__(self, mesh, name='unnamed', integrator='sundials'):
"""Simulation object.
*Arguments*
name : the Simulation name (used for writing data files, for examples)
"""
self.t = 0
self.name = name
self.mesh = mesh
self.n = mesh.n
self.n_nonzero = mesh.n
self.unit_length = mesh.unit_length
self._alpha = np.zeros(self.n, dtype=np.float)
self._Ms = np.zeros(self.n, dtype=np.float)
self._Ms_inv = np.zeros(self.n, dtype=np.float)
self.spin = np.ones(3 * self.n, dtype=np.float)
self.spin_last = np.ones(3 * self.n, dtype=np.float)
self._pins = np.zeros(self.n, dtype=np.int32)
self.field = np.zeros(3 * self.n, dtype=np.float)
self.dm_dt = np.zeros(3 * self.n, dtype=np.float)
self._skx_number = np.zeros(self.n, dtype=np.float)
self.interactions = []
self.pin_fun = None
self.integrator_tolerances_set = False
self.step = 0
if integrator == "sundials":
self.integrator = SundialsIntegrator(self.spin, self.sundials_rhs)
elif integrator == "euler" or integrator == "rk4":
self.integrator = StepIntegrator(self.spin, self.step_rhs, integrator)
else:
raise NotImplemented("integrator must be sundials, euler or rk4")
self.saver = DataSaver(self, name + '.txt')
self.saver.entities['E_total'] = {
'unit': '<J>',
'get': lambda sim: sim.compute_energy(),
'header': 'E_total'}
self.saver.entities['m_error'] = {
'unit': '<>',
'get': lambda sim: sim.compute_spin_error(),
'header': 'm_error'}
self.saver.entities['skx_num'] = {
'unit': '<>',
'get': lambda sim: sim.skyrmion_number(),
'header': 'skx_num'}
self.saver.entities['rhs_evals'] = {
'unit': '<>',
'get': lambda sim: self.integrator.rhs_evals,
'header': 'rhs_evals'}
self.saver.entities['real_time'] = {
'unit': '<s>',
'get': lambda _: time.time(), # seconds since epoch
'header': 'real_time'}
self.saver.update_entity_order()
# This is for old C files codes using the xperiodic variables
self.xperiodic, self.yperiodic, self.zperiodic = mesh.periodicity
self.vtk = SaveVTK(self.mesh, name=name)
self.set_default_options()
class LLG(object):
def __init__(self, mesh, name='unnamed', integrator='sundials'):
"""Simulation object.
*Arguments*
name : the Simulation name (used for writing data files, for examples)
"""
self.t = 0
self.name = name
self.mesh = mesh
self.n = mesh.n
self.n_nonzero = mesh.n
self.unit_length = mesh.unit_length
self._alpha = np.zeros(self.n, dtype=np.float)
self._Ms = np.zeros(self.n, dtype=np.float)
self._Ms_inv = np.zeros(self.n, dtype=np.float)
self.spin = np.ones(3 * self.n, dtype=np.float)
self.spin_last = np.ones(3 * self.n, dtype=np.float)
self._pins = np.zeros(self.n, dtype=np.int32)
self.field = np.zeros(3 * self.n, dtype=np.float)
self.dm_dt = np.zeros(3 * self.n, dtype=np.float)
self._skx_number = np.zeros(self.n, dtype=np.float)
self.interactions = []
self.pin_fun = None
self.integrator_tolerances_set = False
self.step = 0
if integrator == "sundials":
self.integrator = SundialsIntegrator(self.spin, self.sundials_rhs)
elif integrator == "euler" or integrator == "rk4":
self.integrator = StepIntegrator(self.spin, self.step_rhs, integrator)
else:
raise NotImplemented("integrator must be sundials, euler or rk4")
self.saver = DataSaver(self, name + '.txt')
self.saver.entities['E_total'] = {
'unit': '<J>',
'get': lambda sim: sim.compute_energy(),
'header': 'E_total'}
self.saver.entities['m_error'] = {
'unit': '<>',
'get': lambda sim: sim.compute_spin_error(),
'header': 'm_error'}
self.saver.entities['skx_num'] = {
'unit': '<>',
'get': lambda sim: sim.skyrmion_number(),
'header': 'skx_num'}
self.saver.entities['rhs_evals'] = {
'unit': '<>',
'get': lambda sim: self.integrator.rhs_evals,
'header': 'rhs_evals'}
self.saver.entities['real_time'] = {
'unit': '<s>',
'get': lambda _: time.time(), # seconds since epoch
'header': 'real_time'}
self.saver.update_entity_order()
# This is for old C files codes using the xperiodic variables
self.xperiodic, self.yperiodic, self.zperiodic = mesh.periodicity
self.vtk = SaveVTK(self.mesh, name=name)
self.set_default_options()
def set_default_options(self, gamma=2.21e5, Ms=8.0e5, alpha=0.1):
self.default_c = 1e11
self._alpha[:] = alpha
self._Ms[:] = Ms
self.gamma = gamma
self.do_precession = True
def reset_integrator(self, t=0):
self.integrator.reset(self.spin, t)
self.t = t # also reinitialise the simulation time and step
self.step = 0
def set_tols(self, rtol=1e-8, atol=1e-10, max_ord=None, reset=True):
if max_ord is not None:
self.integrator.set_tols(rtol=rtol, atol=atol, max_ord=max_ord)
else:
# not all integrators have max_ord (only VODE does)
# and we don't want to encode a default value here either
self.integrator.set_tols(rtol=rtol, atol=atol)
if reset:
self.reset_integrator(self.t)
def set_m(self, m0=(1, 0, 0), normalise=True):
self.spin[:] = helper.init_vector(m0, self.mesh, normalise)
# TODO: carefully checking and requires to call set_mu first
self.spin.shape = (-1, 3)
for i in range(self.spin.shape[0]):
if self._Ms[i] == 0:
self.spin[i, :] = 0
self.spin.shape = (-1,)
self.integrator.set_initial_value(self.spin, self.t)
def get_pins(self):
return self._pins
def set_pins(self, pin):
self._pins[:] = helper.init_scalar(pin, self.mesh)
for i in range(len(self._Ms)):
if self._Ms[i] == 0.0:
self._pins[i] = 1
pins = property(get_pins, set_pins)
def get_alpha(self):
return self._alpha
def set_alpha(self, value):
self._alpha[:] = helper.init_scalar(value, self.mesh)
alpha = property(get_alpha, set_alpha)
def get_Ms(self):
return self._Ms
def set_Ms(self, value):
self._Ms[:] = helper.init_scalar(value, self.mesh)
nonzero = 0
for i in range(self.n):
if self._Ms[i] > 0.0:
self._Ms_inv = 1.0 / self._Ms[i]
nonzero += 1
self.n_nonzero = nonzero
for i in range(len(self._Ms)):
if self._Ms[i] == 0.0:
self._pins[i] = 1
self.Ms_const = np.max(self._Ms)
Ms = property(get_Ms, set_Ms)
def add(self, interaction, save_field=False):
interaction.setup(self.mesh, self.spin, Ms=self._Ms)
# TODO: FIX
for i in self.interactions:
if i.name == interaction.name:
interaction.name = i.name + '_2'
self.interactions.append(interaction)
energy_name = 'E_{0}'.format(interaction.name)
self.saver.entities[energy_name] = {
'unit': '<J>',
'get': lambda sim: sim.get_interaction(interaction.name).compute_energy(),
'header': energy_name}
if save_field:
fn = '{0}'.format(interaction.name)
self.saver.entities[fn] = {
'unit': '<>',
'get': lambda sim: sim.get_interaction(interaction.name).average_field(),
'header': ('%s_x' % fn, '%s_y' % fn, '%s_z' % fn)}
self.saver.update_entity_order()
def get_interaction(self, name):
for interaction in self.interactions:
if interaction.name == name:
return interaction
else:
raise ValueError("Failed to find the interaction with name '{0}', "
"available interactions: {1}.".format(
name, [x.name for x in self.interactions]))
def run_until(self, t):
if t <= self.t:
if t == self.t and self.t == 0.0:
self.compute_effective_field(t)
self.saver.save()
return
self.spin_last[:] = self.spin[:]
flag = self.integrator.run_until(t)
if flag < 0:
raise Exception("Run cython run_until failed!!!")
self.spin[:] = self.integrator.y[:]
self.t = t
self.step += 1
self.compute_effective_field(t) # update fields before saving data
self.saver.save()
def compute_effective_field(self, t):
#self.spin[:] = y[:]
self.field[:] = 0
for obj in self.interactions:
self.field += obj.compute_field(t)
def sundials_rhs(self, t, y, ydot):
self.t = t
# already synchronized when call this funciton
# self.spin[:]=y[:]
self.compute_effective_field(t)
clib.compute_llg_rhs(ydot,
self.spin,
self.field,
self.alpha,
self._pins,
self.gamma,
self.n,
self.do_precession,
self.default_c)
#ydot[:] = self.dm_dt[:]
return 0
def step_rhs(self, t, y):
self.t = t
self.compute_effective_field(t)
clib.compute_llg_rhs(self.dm_dt,
self.spin,
self.field,
self.alpha,
self._pins,
self.gamma,
self.n,
self.do_precession,
self.default_c)
return self.dm_dt
def compute_average(self):
self.spin.shape = (-1, 3)
average = np.sum(self.spin, axis=0) / self.n_nonzero
self.spin.shape = (3 * self.n)
return average
def compute_energy(self):
energy = 0
for obj in self.interactions:
energy += obj.compute_energy()
return energy
def skyrmion_number(self):
nx = self.mesh.nx
ny = self.mesh.ny
nz = self.mesh.nz
number = clib.compute_skymrion_number(
self.spin, self._skx_number, nx, ny, nz, self.mesh.neighbours)
return number
def spin_at(self, i, j, k):
i1 = 3 * self.mesh.index(i, j, k)
# print self.spin.shape,nxy,nx,i1,i2,i3
return np.array([self.spin[i1],
self.spin[i1 + 1],
self.spin[i1 + 2]])
def add_monitor_at(self, i, j, k, name='p'):
"""
Save site spin with index (i,j,k) to txt file.
"""
self.saver.entities[name] = {
'unit': '<>',
'get': lambda sim: sim.spin_at(i, j, k),
'header': (name + '_x', name + '_y', name + '_z')}
self.saver.update_entity_order()
def save_vtk(self):
self.vtk.save_vtk(self.spin.reshape(-1, 3), self.Ms, step=self.step)
def save_m(self):
if not os.path.exists('%s_npys' % self.name):
os.makedirs('%s_npys' % self.name)
name = '%s_npys/m_%g.npy' % (self.name, self.step)
np.save(name, self.spin)
def save_skx(self):
if not os.path.exists('%s_skx_npys' % self.name):
os.makedirs('%s_skx_npys' % self.name)
name = '%s_skx_npys/m_%g.npy' % (self.name, self.step)
np.save(name, self._skx_number)
def stat(self):
return self.integrator.stat()
def spin_length(self):
self.spin.shape = (3, -1)
length = np.sqrt(np.sum(self.spin**2, axis=0))
self.spin.shape = (-1,)
return length
def compute_spin_error(self):
length = self.spin_length() - 1.0
length[self._pins > 0] = 0
return np.max(abs(length))
def compute_dmdt(self, dt):
m0 = self.spin_last
m1 = self.spin
dm = (m1 - m0).reshape((3, -1))
max_dm = np.max(np.sqrt(np.sum(dm**2, axis=0)))
max_dmdt = max_dm / dt
return max_dmdt
def relax(self, dt=1e-11, stopping_dmdt=0.01, max_steps=1000,
save_m_steps=100, save_vtk_steps=100):
ONE_DEGREE_PER_NS = 17453292.52
for i in range(0, max_steps + 1):
cvode_dt = self.integrator.get_current_step()
increment_dt = dt
if cvode_dt > dt:
increment_dt = cvode_dt
self.run_until(self.t + increment_dt)
if save_vtk_steps is not None:
if i % save_vtk_steps == 0:
self.save_vtk()
if save_m_steps is not None:
if i % save_m_steps == 0:
self.save_m()
dmdt = self.compute_dmdt(increment_dt)
print 'step=%d, time=%g, max_dmdt=%g ode_step=%g' % (self.step,
self.t,
dmdt / ONE_DEGREE_PER_NS,
cvode_dt)
if dmdt < stopping_dmdt * ONE_DEGREE_PER_NS:
break
if save_m_steps is not None:
self.save_m()
if save_vtk_steps is not None:
self.save_vtk()
