def test_exch_field_oommf(A=1e-11, Ms=2.6e5):
"""
Compare the exchange field from Fidimag with an equivalent
OOMMF simulation. OOMMF field data is taken from an OVF file.
"""
mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
# An equivalent initial magnetisation for OOMMF
# The spatial variables are rescale since they are in nm
init_m0 = (r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] '
+ r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] '
+ r'0 '
+ r'] ')
field_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
# Test if the maximum relative errors between both simulations
# is small enough, for every field component
assert max([mx0, mx1, mx2]) < 1e-12
def test_exch_field_oommf(A=1e-11, Ms=2.6e5):
mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),
'omfs',
'test_exch_field_oommf.ohf'
)
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
#field_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
def test_exch_field_oommf(A=1e-11, Ms=2.6e5):
"""
Compare the exchange field from Fidimag with an equivalent
OOMMF simulation. OOMMF field data is taken from an OVF file.
"""
mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
# An equivalent initial magnetisation for OOMMF
# The spatial variables are rescale since they are in nm
init_m0 = (
r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] ' +
r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] ' + r'0 ' + r'] ')
field_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
# Test if the maximum relative errors between both simulations
# is small enough, for every field component
assert max([mx0, mx1, mx2]) < 1e-12
def test_exch_field_oommf(A=1e-11, Ms=2.6e5):
mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),
'omfs',
'test_exch_field_oommf.ohf'
)
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
#field_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
def relax_system(mesh):
sim = Sim(mesh, name='relax')
sim.driver.set_tols(rtol=1e-10, atol=1e-10)
sim.driver.alpha = 0.1
sim.driver.gamma = 2.211e5
sim.Ms = spatial_Ms
print(sim.Ms)
sim.set_m(init_m)
A = 1.3e-11
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
dmi = DMI(D=4e-3)
sim.add(dmi)
dmi2 = DMI(D=2e-3, dmi_type="interfacial")
sim.add(dmi2)
anis = UniaxialAnisotropy(-3e4, axis=(0, 0, 1))
sim.add(anis)
sim.relax(dt=1e-13,
stopping_dmdt=5e4,
max_steps=5000,
save_m_steps=100,
save_vtk_steps=50)
#np.save('m0.npy', sim.spin)
fd = demag.compute_field(sim.spin)
fe = exch.compute_field(sim.spin)
fdmi = dmi.compute_field(sim.spin)
fdmi2 = dmi2.compute_field(sim.spin)
fanis = anis.compute_field(sim.spin)
np.savetxt(
"test_fields.txt",
np.transpose([
np.concatenate((sim.Ms, sim.Ms, sim.Ms, [0.0])),
np.concatenate((sim.spin, [100])),
np.concatenate((fd, [demag.compute_energy()])),
np.concatenate((fe, [exch.compute_energy()])),
np.concatenate((fdmi, [dmi.compute_energy()])),
np.concatenate((fdmi2, [dmi2.compute_energy()])),
np.concatenate((fanis, [anis.compute_energy()]))
]),
header=
"Generated by Fidimag. Size=20x5x3, 2.5nm x 2.5nm x 3nm, Ms=8.0e5A/m, A=1.3e-11 J/m,"
+
" D=4e-3 J/m^2, D_int=2e-3 J/m^2, Ku=-3e4 J/m^3 axis=(0,0,1).\n Ms "
+ "".ljust(20) + " m0 " + "".ljust(20) + "demag" + "".ljust(20) +
"exch" + "".ljust(22) + "dmi" + "".ljust(22) + "dmi_interfacial" +
"".ljust(22) + "anis")
def test_with_oommf_spatial_Ms(A=1e-11):
def spatial_Ms(pos):
x, y = pos[0], pos[1]
if x**2 + y**2 < 5**2:
return 2e4
else:
return 0
init_m0 = (
r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] ' +
r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] ' + r'0 ' + r'] ')
init_Ms = """
if { ($x * $x + $y * $y) < 5e-9 * 5e-9 } {
return 2e4
} else {
return 0
}
"""
mesh = CuboidMesh(nx=12, ny=10, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = spatial_Ms
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
field = exch.compute_field()
field_oommf = compute_exch_field(mesh,
init_m0=init_m0,
A=A,
spatial_Ms=init_Ms)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
field = demag.compute_field()
field_oommf = compute_demag_field(mesh,
spatial_Ms=init_Ms,
init_m0=init_m0)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-11
def test_with_oommf_spatial_Ms(A=1e-11):
def spatial_Ms(pos):
x, y = pos[0], pos[1]
if x ** 2 + y ** 2 < 5 ** 2:
return 2e4
else:
return 0
init_m0 = (r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] '
+ r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] '
+ r'0 '
+ r'] ')
init_Ms = """
if { ($x * $x + $y * $y) < 5e-9 * 5e-9 } {
return 2e4
} else {
return 0
}
"""
mesh = CuboidMesh(nx=12, ny=10, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = spatial_Ms
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
field = exch.compute_field()
field_oommf = compute_exch_field(
mesh, init_m0=init_m0, A=A, spatial_Ms=init_Ms)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
field = demag.compute_field()
field_oommf = compute_demag_field(
mesh, spatial_Ms=init_Ms, init_m0=init_m0)
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-11
def test_exch_1d(do_plot=False):
# Initiate the 1D mesh and magnetisation as before
mesh = CuboidMesh(nx=100, ny=1, nz=1)
sim = Sim(mesh)
sim.set_m(init_m)
# Simplify the magnetic parameters
mu0 = 4 * np.pi * 1e-7
sim.Ms = 1.0 / mu0
exch = UniformExchange(1)
sim.add(exch)
# Compute the exchange field and reshape it in order
# to leave every row as the [f_x, f_y, f_z] array
# for every spin
field = exch.compute_field()
field.shape = (-1, 3)
# We know that the field in x is always zero ( see the
# analytical calculation at the beginning)
assert max(abs(field[:, 0])) == 0
# These are the analytical values for the exchange field in y,z
# In this case, k=0.1 , then 2 * k^2 evaluates as 0.02
xs = np.linspace(0, 99, 100)
epy = -0.02 * np.sin(0.1 * xs)
epz = -0.02 * np.cos(0.1 * xs)
# Compare the analytical value
# of the y component of the exchange field, with Fidimag's
# result (second column of the reshaped field array)
# WARNING: NOTICE that we are not considering the extremes since
# there is a wrong expression in the border of the exchange field
# with NO PBCs. We must FIX this test!
assert max(abs(epy[1:-1] - field[1:-1, 1])) < 3e-5
if do_plot:
plt.plot(xs, field[:, 1], "-.", label="my", color='DarkGreen')
plt.plot(xs, field[:, 2], "-.", label="mz", color='DarkGreen')
plt.plot(xs, epy, "--", label="analytical", color='b')
plt.plot(xs, epz, "--", color='r')
plt.xlabel("xs")
plt.ylabel("field")
plt.legend()
plt.savefig("exchange_field.pdf")
def test_demag_field_oommf_large(Ms=8e5, A=1.3e-11):
mesh = CuboidMesh(nx=150, ny=50, nz=1, dx=2.5, dy=2.5, dz=3, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
demag_field = demag.compute_field()
exch_field = exch.compute_field()
#exact = demag.compute_exact()
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
#demag_oommf = compute_demag_field(mesh, Ms=Ms, init_m0=init_m0)
#exch_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_demag_field_oommf_large_Demag.ohf')
ovf = OMF2(omf_file)
demag_oommf = ovf.get_all_mags()
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_demag_field_oommf_large_Exchange.ohf')
ovf = OMF2(omf_file)
exch_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(demag_oommf, demag_field)
#print mx0, mx1, mx2
assert max([mx0,mx1,mx2])< 5e-10
mx0, mx1, mx2 = compare_fields(exch_oommf, exch_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 1e-11
def test_demag_field_oommf_large(Ms=8e5, A=1.3e-11):
mesh = CuboidMesh(nx=150, ny=50, nz=1, dx=2.5, dy=2.5, dz=3, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
demag_field = demag.compute_field()
exch_field = exch.compute_field()
#exact = demag.compute_exact()
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
#demag_oommf = compute_demag_field(mesh, Ms=Ms, init_m0=init_m0)
#exch_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_demag_field_oommf_large_Demag.ohf')
ovf = OMF2(omf_file)
demag_oommf = ovf.get_all_mags()
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_demag_field_oommf_large_Exchange.ohf')
ovf = OMF2(omf_file)
exch_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(demag_oommf, demag_field)
#print mx0, mx1, mx2
assert max([mx0,mx1,mx2])< 5e-10
mx0, mx1, mx2 = compare_fields(exch_oommf, exch_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 1e-11
def test_demag_field_oommf_large(Ms=8e5, A=1.3e-11):
mesh = CuboidMesh(nx=150,
ny=50,
nz=1,
dx=2.5,
dy=2.5,
dz=3,
unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
demag_field = demag.compute_field()
exch_field = exch.compute_field()
#exact = demag.compute_exact()
init_m0 = (
r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] ' +
r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] ' + r'0 ' + r'] ')
demag_oommf = compute_demag_field(mesh, Ms=Ms, init_m0=init_m0)
exch_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(demag_oommf, demag_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 5e-10
mx0, mx1, mx2 = compare_fields(exch_oommf, exch_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 1e-11
def test_demag_field_oommf_large(Ms=8e5, A=1.3e-11):
mesh = CuboidMesh(nx=150, ny=50, nz=1, dx=2.5, dy=2.5, dz=3, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
demag_field = demag.compute_field()
exch_field = exch.compute_field()
#exact = demag.compute_exact()
init_m0 = (r'return [list [expr {sin($x * 1e9) + $y * 1e9 + $z * 2.3e9}] '
+ r' [expr {cos($x * 1e9) + $y * 1e9 + $z * 1.3e9}] '
+ r'0 '
+ r'] ')
demag_oommf = compute_demag_field(mesh, Ms=Ms, init_m0=init_m0)
exch_oommf = compute_exch_field(mesh, Ms=Ms, init_m0=init_m0, A=A)
mx0, mx1, mx2 = compare_fields(demag_oommf, demag_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 5e-10
mx0, mx1, mx2 = compare_fields(exch_oommf, exch_field)
#print mx0, mx1, mx2
assert max([mx0, mx1, mx2]) < 1e-11
def test_with_oommf_spatial_Ms(A=1e-11):
def spatial_Ms(pos):
x, y = pos[0], pos[1]
if x**2 + y**2 < 5**2:
return 2e4
else:
return 0
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
init_Ms = """
if { $x*$x + $y*$y < 5e-9*5e-9 } {
return 2e4
} else {
return 0
}
"""
mesh = CuboidMesh(nx=12, ny=10, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = spatial_Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
#field_oommf = compute_exch_field(mesh, init_m0=init_m0, A=A, spatial_Ms=init_Ms)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_with_oommf_spatial_Ms_Exchange.ohf')
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
field = demag.compute_field()
#field_oommf = compute_demag_field(mesh, spatial_Ms=init_Ms, init_m0=init_m0)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_with_oommf_spatial_Ms_Demag.ohf')
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-11
def test_with_oommf_spatial_Ms(A=1e-11):
def spatial_Ms(pos):
x, y = pos[0], pos[1]
if x**2 + y**2 < 5**2:
return 2e4
else:
return 0
init_m0 = """
return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 0]
"""
init_Ms = """
if { $x*$x + $y*$y < 5e-9*5e-9 } {
return 2e4
} else {
return 0
}
"""
mesh = CuboidMesh(nx=12, ny=10, nz=2, dx=0.5, unit_length=1e-9)
sim = Sim(mesh)
sim.Ms = spatial_Ms
exch = UniformExchange(A=A)
sim.add(exch)
demag = Demag()
sim.add(demag)
def init_m(pos):
x, y, z = pos
return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 0)
sim.set_m(init_m)
field = exch.compute_field()
#field_oommf = compute_exch_field(mesh, init_m0=init_m0, A=A, spatial_Ms=init_Ms)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_with_oommf_spatial_Ms_Exchange.ohf')
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-12
field = demag.compute_field()
#field_oommf = compute_demag_field(mesh, spatial_Ms=init_Ms, init_m0=init_m0)
omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_with_oommf_spatial_Ms_Demag.ohf')
ovf = OMF2(omf_file)
field_oommf = ovf.get_all_mags()
mx0, mx1, mx2 = compare_fields(field_oommf, field)
assert max([mx0, mx1, mx2]) < 1e-11
