def test_script_missing_terms(self):
# Missing Gilbert damping alpha
self.system.dynamics = oc.Precession(gamma=2.2)
td = oc.TimeDriver()
script = td.script(self.system, t=1e-9, n=20)
assert "alpha 0" in script
assert "gamma_G 2.2" in script
# Missing gamma
self.system.dynamics = oc.Damping(alpha=5)
td = oc.TimeDriver()
script = td.script(self.system, t=1e-9, n=20)
assert "alpha 5" in script
assert "gamma_G 221100" in script
def overhead():
"""Run a macrospin example for 1 ps through oommfc and directly and
return the difference in run times.
Returns
-------
overhead : float
The time difference (overhead) between running OOMMF though
oommfc and directly
"""
# Running OOMMF through oommfc.
system = oc.examples.macrospin()
td = oc.TimeDriver()
oommfc_start = time.time()
td.drive(system, t=1e-12, n=1)
oommfc_stop = time.time()
oommfc_time = oommfc_stop - oommfc_start
# Running OOMMF directly.
oommf_runner = get_oommf_runner()
mifpath = os.path.realpath('example-macrospin/example-macrospin.mif')
oommf_start = time.time()
oommf_runner.call(mifpath)
oommf_stop = time.time()
oommf_time = oommf_stop - oommf_start
return oommfc_time - oommf_time
def status():
"""Run a macrospin example for 1 ps through oommfc and print the OOMMF
status.
Returns
-------
int
If ``0``, the OOMMF is found and running. Otherwise, ``1`` is returned.
Examples
--------
1. Checking the OOMMF status.
>>> import oommfc as oc
...
>>> oc.oommf.status()
Running OOMMF...
OOMMF found and running.
0
"""
system = mm.examples.macrospin()
try:
td = oc.TimeDriver()
td.drive(system, t=1e-12, n=1)
print('OOMMF found and running.')
return 0
except (EnvironmentError, RuntimeError):
print('Cannot find OOMMF.')
return 1
def test_script(self):
driver = oc.TimeDriver()
t = 1e-9
n = 120
script = driver.script(self.system, t=t, n=n)
assert script[0] == "#"
assert script[-1] == "1"
assert script.count("#") == 3
assert script.count("Specify") == 2
assert script.count("Destination") == 2
assert script.count("Schedule") == 2
assert script.count("mmArchive") == 2
assert script.count("Stage") == 2
assert "Oxs_RungeKuttaEvolve" in script
assert "Oxs_TimeDriver" in script
assert "Oxs_FileVectorField" in script
lines = script.split("\n")
alpha = self.system.dynamics.damping.alpha
assert lines[2] == " alpha {}".format(alpha)
gamma = self.system.dynamics.precession.gamma
assert lines[3] == " gamma_G {}".format(gamma)
assert lines[9] == " stopping_time {}".format(t / n)
assert lines[11] == " stage_count {}".format(n)
assert lines[12] == " Ms {}".format(8e5)
assert lines[17] == " file m0.omf"
assert lines[20] == " basename tds"
def status():
"""Run a macrospin example for 1 ps through oommfc and print the OOMMF
status.
"""
try:
system = oc.examples.macrospin()
td = oc.TimeDriver()
td.drive(system, t=1e-12, n=1)
print('OOMMF found and running.')
return 0
except (EnvironmentError, RuntimeError):
print("Cannot find OOMMF.")
return 1
def test_stdprob5():
name = "stdprob5"
# Remove any previous simulation directories.
if os.path.exists(name):
shutil.rmtree(name)
# Geometry
lx = 100e-9 # x dimension of the sample(m)
ly = 100e-9 # y dimension of the sample (m)
lz = 10e-9 # sample thickness (m)
# Material (permalloy) parameters
Ms = 8e5 # saturation magnetisation (A/m)
A = 1.3e-11 # exchange energy constant (J/m)
# Dynamics (LLG + STT equation) parameters
gamma = 2.211e5 # gyromagnetic ratio (m/As)
alpha = 0.1 # Gilbert damping
ux = -72.35 # velocity in x direction
beta = 0.05 # non-adiabatic STT parameter
system = oc.System(name=name)
mesh = oc.Mesh(p1=(0, 0, 0),
p2=(100e-9, 100e-9, 10e-9),
cell=(5e-9, 5e-9, 5e-9))
system.mesh = mesh
system.hamiltonian = oc.Exchange(A) + oc.Demag()
def m_vortex(pos):
x, y, z = pos[0] / 1e-9 - 50, pos[1] / 1e-9 - 50, pos[2] / 1e-9
return (-y, x, 10)
system.m = df.Field(mesh, value=m_vortex, normalisedto=Ms)
md = oc.MinDriver()
md.drive(system)
system.dynamics += oc.Precession(gamma) + oc.Damping(alpha) + \
oc.STT(u=(ux, 0, 0), beta=beta)
td = oc.TimeDriver()
td.drive(system, t=8e-9, n=100)
mx = system.dt["mx"].as_matrix()
assert -0.03 < mx.max() < 0
assert -0.35 < mx.min() < -0.30
shutil.rmtree(name)
def test_save_mif(self):
driver = oc.TimeDriver()
t = 1e-9
n = 120
driver._makedir(self.system)
driver._save_mif(self.system, t=t, n=n)
miffilename = os.path.join("tds", "tds.mif")
assert os.path.isfile(miffilename)
lines = open(miffilename, "r").readlines()
assert lines[0] == "# MIF 2.1\n"
assert lines[-1][-1] == "1"
shutil.rmtree("tds")
def effective_field(self):
_dict = {
"Demag": "Oxs_Demag::Field",
"Exchange": "Oxs_UniformExchange::Field",
"UniaxialAnisotropy": "Oxs_UniaxialAnisotropy::Field",
"Zeeman": "Oxs_FixedZeeman::Field",
"Hamiltonian": "Oxs_RungeKuttaEvolve:evolver:Total field"
}
td = oc.TimeDriver()
td.drive(self.system, derive=_dict[self.cls])
dirname = os.path.join(self.system.name, "")
ohf_file = max(glob.iglob("{}*.ohf".format(dirname)),
key=os.path.getctime)
return df.read(ohf_file)
def energy(self):
_dict = {
"Demag": "Demag::Energy",
"Exchange": "UniformExchange::Energy",
"UniaxialAnisotropy": "UniaxialAnisotropy::Energy",
"Zeeman": "FixedZeeman::Energy",
"Hamiltonian": "RungeKuttaEvolve:evolver:Totalenergy"
}
td = oc.TimeDriver()
td.drive(self.system, derive="energy")
dirname = os.path.join(self.system.name, "")
odt_file = max(glob.iglob("{}*.odt".format(dirname)),
key=os.path.getctime)
dt = oommfodt.read(odt_file, replace_columns=False)
return dt[_dict[self.cls]][0]
def test_stdprobfmr():
name = "stdprobfmr"
# Remove any previous simulation directories.
if os.path.exists(name):
shutil.rmtree(name)
lx = ly = 120e-9 # x and y dimensions of the sample(m)
lz = 10e-9 # sample thickness (m)
dx = dy = dz = 10e-9 # discretisation in x, y, and z directions (m)
Ms = 8e5 # saturation magnetisation (A/m)
A = 1.3e-11 # exchange energy constant (J/m)
H = 8e4 * np.array([0.81345856316858023, 0.58162287266553481, 0.0])
alpha = 0.008 # Gilbert damping
gamma = 2.211e5
mesh = oc.Mesh(p1=(0, 0, 0), p2=(lx, ly, lz), cell=(dx, dy, dz))
system = oc.System(name="stdprobfmr")
system.hamiltonian = oc.Exchange(A) + oc.Demag() + oc.Zeeman(H)
system.dynamics = oc.Precession(gamma) + oc.Damping(alpha)
system.m = df.Field(mesh, value=(0, 0, 1), norm=Ms)
md = oc.MinDriver()
md.drive(system)
H = 8e4 * np.array([0.81923192051904048, 0.57346234436332832, 0.0])
system.hamiltonian.zeeman.H = H
T = 20e-9
n = 4000
td = oc.TimeDriver()
td.drive(system, t=T, n=n)
t = system.dt['t'].as_matrix()
my = system.dt['mx'].as_matrix()
psd = np.log10(np.abs(scipy.fftpack.fft(my))**2)
f_axis = scipy.fftpack.fftfreq(4000, d=20e-9/4000)
shutil.rmtree(name)
def test_drive(self):
md = oc.TimeDriver()
md.drive(self.system, t=0.1e-9, n=10)
assert os.path.exists("tds")
miffilename = os.path.join("tds", "tds.mif")
assert os.path.isfile(miffilename)
omf_files = list(glob.iglob("tds/*.omf"))
odt_files = list(glob.iglob("tds/*.odt"))
assert len(omf_files) == 11
omffilename = os.path.join("tds", "m0.omf")
assert omffilename in omf_files
assert len(odt_files) == 1
shutil.rmtree("tds")
def energy_density(self):
_dict = {
"Demag": "Oxs_Demag::Energy density",
"Exchange": "Oxs_UniformExchange::Energy density",
"UniaxialAnisotropy": ("Oxs_UniaxialAnisotropy::"
"Energy density"),
"Zeeman": "Oxs_FixedZeeman::Energy density",
"Hamiltonian": ("Oxs_RungeKuttaEvolve:evolver:"
"Total energy density")
}
td = oc.TimeDriver()
td.drive(self.system, derive=_dict[self.cls])
dirname = os.path.join(self.system.name, "")
oef_file = max(glob.iglob("{}*.oef".format(dirname)),
key=os.path.getctime)
return df.read(oef_file)
def overhead():
"""Run a macrospin example for 1 ps through ``oommfc`` and directly and
return the difference in run times.
Returns
-------
float
The time difference (overhead) between running OOMMF though ``oommfc``
and directly.
Examples
--------
1. Getting the overhead time.
>>> import oommfc as oc
...
>>> isinstance(oc.oommf.overhead(), float)
Running OOMMF...
True
"""
# Running OOMMF through oommfc.
system = mm.examples.macrospin()
td = oc.TimeDriver()
oommfc_start = time.time()
td.drive(system, t=1e-12, n=1, save=True, overwrite=True)
oommfc_stop = time.time()
oommfc_time = oommfc_stop - oommfc_start
# Running OOMMF directly.
oommf_runner = get_oommf_runner()
mifpath = os.path.realpath(
os.path.join(system.name, 'drive-0', 'macrospin.mif'))
oommf_start = time.time()
oommf_runner.call(mifpath)
oommf_stop = time.time()
oommf_time = oommf_stop - oommf_start
oc.delete(system)
return oommfc_time - oommf_time
def overhead():
"""Run a macrospin example for 1 ps through ``oommfc`` and directly and
return the difference in run times.
Returns
-------
float
The time difference (overhead) between running OOMMF though ``oommfc``
and directly.
Examples
--------
1. Getting the overhead time.
>>> import oommfc as oc
...
>>> isinstance(oc.oommf.overhead(), float)
Running OOMMF...
True
"""
with tempfile.TemporaryDirectory() as workingdir:
with uu.changedir(workingdir):
# Running OOMMF through oommfc.
system = mm.examples.macrospin()
td = oc.TimeDriver()
oommfc_start = time.time()
td.drive(system, t=1e-12, n=1)
oommfc_stop = time.time()
oommfc_time = oommfc_stop - oommfc_start
# Running OOMMF directly.
oommf_runner = oc.runner.runner
mifpath = pathlib.Path(f"{system.name}/drive-0/macrospin.mif").resolve()
oommf_start = time.time()
oommf_runner.call(str(mifpath))
oommf_stop = time.time()
oommf_time = oommf_stop - oommf_start
return oommfc_time - oommf_time
def test_silent(capsys):
md = oc.MinDriver()
md.drive(mm.examples.macrospin())
captured = capsys.readouterr()
assert "Running OOMMF" in captured.out
assert captured.err == ""
md.drive(mm.examples.macrospin(), verbose=2)
captured = capsys.readouterr()
assert "Running OOMMF" in captured.out
assert captured.err == ""
td = oc.TimeDriver()
td.drive(mm.examples.macrospin(), t=1e-10, n=10, verbose=2)
captured = capsys.readouterr()
assert captured.out == ""
assert "files written" in captured.err # tqdm output on stderr
md.drive(mm.examples.macrospin(), verbose=0)
captured = capsys.readouterr()
assert captured.out == ""
assert captured.err == ""
def compute(func, system):
"""Computes a particular value of an energy term or energy container
(``energy``, ``density``, or ``effective_field``).
Parameters
----------
func : callable
A property of an energy term or an energy container.
system : micromagneticmodel.System
Micromagnetic system for which the property is calculated.
Returns
-------
numbers.Real, discretisedfield.Field
Resulting value.
Examples
--------
1. Computing values of energy terms.
>>> import micromagneticmodel as mm
>>> import oommfc as oc
...
>>> system = mm.examples.macrospin()
>>> oc.compute(system.energy.zeeman.energy, system)
Running OOMMF...
-8.8...e-22
>>> oc.compute(system.energy.effective_field, system)
Running OOMMF...
Field(...)
>>> oc.compute(system.energy.density, system)
Running OOMMF...
Field(...)
"""
td = oc.TimeDriver(total_iteration_limit=1)
td.drive(system,
t=1e-25,
n=1,
append=True,
compute=schedule_script(func, system))
if func.__name__ == 'energy':
extension = '*.odt'
elif func.__name__ == 'effective_field':
extension = '*.ohf'
elif func.__name__ == 'density':
extension = '*.oef'
dirname = os.path.join(system.name, f'compute-{system.compute_number-1}')
output_file = max(glob.iglob(os.path.join(dirname, extension)),
key=os.path.getctime)
if func.__name__ == 'energy':
table = ut.Table.fromfile(output_file, rename=False)
if isinstance(func.__self__, mm.Energy):
output = table.data['RungeKuttaEvolve:evolver:Total energy'][0]
else:
output = table.data[(f'{oxs_class(func.__self__, system)}:'
f'{func.__self__.name}:Energy')][0]
else:
output = df.Field.fromfile(output_file)
return output
def test_drive_exception(self):
md = oc.TimeDriver()
with pytest.raises(ValueError):
md.drive(self.system, t=-0.1e-9, n=10)
with pytest.raises(ValueError):
md.drive(self.system, t=0.1e-9, n=-10)
def test_stdprob4():
name = "stdprob4"
# Remove any previous simulation directories.
if os.path.exists(name):
shutil.rmtree(name)
L, d, th = 500e-9, 125e-9, 3e-9 # (m)
cellsize = (5e-9, 5e-9, 3e-9) # (m)
mesh = oc.Mesh((0, 0, 0), (L, d, th), cellsize)
system = oc.System(name=name)
A = 1.3e-11 # (J/m)
system.hamiltonian = oc.Exchange(A) + oc.Demag()
gamma = 2.211e5 # (m/As)
alpha = 0.02
system.dynamics = oc.Precession(gamma) + oc.Damping(alpha)
Ms = 8e5 # (A/m)
system.m = df.Field(mesh, value=(1, 0.25, 0.1), norm=Ms)
md = oc.MinDriver()
md.drive(system) # updates system.m in-place
dirname = os.path.join(name, "")
miffilename = os.path.join(name, "{}.mif".format(name))
assert os.path.exists(dirname)
assert os.path.isfile(miffilename)
omf_files = list(glob.iglob("{}/*.omf".format(name)))
odt_files = list(glob.iglob("{}/*.odt".format(name)))
assert len(omf_files) == 2
omffilename = os.path.join(name, "m0.omf")
assert omffilename in omf_files
assert len(odt_files) == 1
shutil.rmtree(name)
H = (-24.6e-3/oc.mu0, 4.3e-3/oc.mu0, 0)
system.hamiltonian += oc.Zeeman(H)
td = oc.TimeDriver()
td.drive(system, t=1e-9, n=200)
dirname = os.path.join(name, "")
miffilename = os.path.join(name, "{}.mif".format(name))
assert os.path.exists(dirname)
assert os.path.isfile(miffilename)
omf_files = list(glob.iglob("{}/*.omf".format(name)))
odt_files = list(glob.iglob("{}/*.odt".format(name)))
assert len(omf_files) == 201
omffilename = os.path.join(name, "m0.omf")
assert omffilename in omf_files
assert len(odt_files) == 1
myplot = system.dt.plot("t", "my")
figfilename = os.path.join(name, "stdprob4-t-my.pdf")
myplot.figure.savefig(figfilename)
assert os.path.isfile(figfilename)
t = system.dt["t"].as_matrix()
my = system.dt["my"].as_matrix()
assert abs(min(t) - 5e-12) < 1e-20
assert abs(max(t) - 1e-9) < 1e-20
# Eye-norm test.
assert 0.7 < max(my) < 0.8
assert -0.5 < min(my) < -0.4
shutil.rmtree(name)
>>> oc.compute(system.energy.zeeman.energy, system)
Running OOMMF...
-8.8...e-22
>>> oc.compute(system.energy.effective_field, system)
Running OOMMF...
Field(...)
>>> oc.compute(system.energy.density, system)
Running OOMMF...
Field(...)
"""
if system.T > 0:
raise RuntimeError("`oc.compute` does not support finite temperature."
f" (Temperature is specified as {system.T=})")
td = oc.TimeDriver(total_iteration_limit=1)
workingdir = td._setup_working_directory(system=system,
dirname=dirname,
mode="compute",
append=append)
with uu.changedir(workingdir):
td.write_mif(
system=system,
t=1e-25,
n=1,
ovf_format=ovf_format,
compute=schedule_script(func, system),
)
td._call(system=system,
runner=runner,
n_threads=n_threads,
shutil.rmtree(name) L = 30e-9 # (m) cellsize = (10e-9, 15e-9, 5e-9) # (m) mesh = oc.Mesh((0, 0, 0), (L, L, L), cellsize) system = oc.System(name=name) A = 1.3e-11 # (J/m) H = (1e6, 0.0, 2e5) system.hamiltonian = oc.Exchange(A=A) + oc.Zeeman(H=H) gamma = 2.211e5 # (m/As) alpha = 0.02 system.dynamics = oc.Precession(gamma) + oc.Damping(alpha) Ms = 8e5 # (A/m) system.m = df.Field(mesh, value=(0.0, 0.25, 0.1), norm=Ms) td = oc.TimeDriver() td.drive(system, t=25e-12, n=25) # updates system.m in-place td.drive(system, t=15e-12, n=15) td.drive(system, t=5e-12, n=10) md = oc.MinDriver() md.drive(system) system.hamiltonian.zeeman.H = (0.0, 0.0, 1.0e6) td.drive(system, t=5e-12, n=5) md.drive(system)
import oommfc as mc # import mumaxc as mc import discretisedfield as df L = 10e-9 d = 1e-9 Ms = 8e6 # saturation magnetisation (A/m) A = 1e-12 # exchange energy constant (J/m) H = (5e6, 0, 0) # external magnetic field in the x-direction (A/m) gamma = 2.211e5 # gamma parameter (m/As) alpha = 0.2 # Gilbert damping mesh = mc.Mesh(p1=(0, 0, 0), p2=(L, L, L), cell=(d, d, d)) system = mc.System(name='example2') system.hamiltonian = mc.Exchange(A=A) + mc.Demag() + mc.Zeeman(H=H) system.dynamics = mc.Precession(gamma=gamma) + mc.Damping(alpha=alpha) system.m = df.Field(mesh, value=(0, 0, 1), norm=Ms) td = mc.TimeDriver() td.drive(system, t=1e-9, n=10, overwrite=True) mx, my, mz = system.m.average assert mx > my assert mx > mz print(system.m.average)
