Python Sim.Ms方法代码示例

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def apply_field1(mesh):

    sim = Sim(mesh, name='dyn')

    sim.set_tols(rtol=1e-10, atol=1e-10)
    sim.alpha = 0.02
    sim.gamma = 2.211e5
    sim.Ms = 8.0e5

    sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag()
    sim.add(demag)

    mT = 0.001 / mu0
    print("Applied field = {}".format(mT))

    zeeman = Zeeman([-24.6 * mT, 4.3 * mT, 0], name='H')
    sim.add(zeeman, save_field=True)

    ts = np.linspace(0, 1e-9, 201)
    for t in ts:
        sim.run_until(t)
        print('sim t=%g' % t)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def relax_system(mesh):

    sim = Sim(mesh, chi=1e-3, name='relax', driver='llbar_full')

    sim.driver.set_tols(rtol=1e-7, atol=1e-7)
    sim.Ms = 8.0e5
    sim.driver.alpha = 0.1
    sim.beta = 0
    sim.driver.gamma = 2.211e5

    sim.set_m((1, 0.25, 0.1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    mT = 795.7747154594767
    zeeman = Zeeman([-100 * mT, 4.3 * mT, 0], name='H')
    sim.add(zeeman, save_field=True)

    demag = Demag()
    sim.add(demag)

    ONE_DEGREE_PER_NS = 17453292.52

    sim.relax(dt=1e-12, stopping_dmdt=0.01,
              max_steps=5000, save_m_steps=100, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def relax_system(mesh):

    sim = Sim(mesh, name="relax")

    sim.driver.set_tols(rtol=1e-10, atol=1e-14)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 2e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000, save_m_steps=None, save_vtk_steps=50)

    np.save("m0.npy", sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def test_dmi_field_oommf(D=4.1e-3, Ms=2.6e5):

    mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)

    sim = Sim(mesh)
    sim.Ms = Ms

    dmi = DMI(D=D, dmi_type='interfacial')
    sim.add(dmi)

    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 = dmi.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]
        """
    # TODO: check the sign of DMI in OOMMF.
    #field_oommf = compute_dmi_field(mesh, Ms=Ms, init_m0=init_m0, D=-D)
    omf_file = os.path.join(os.path.dirname(os.path.abspath(__file__)),'omfs','test_dmi_field_oommf.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

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def run_fidimag(mesh):

    mu0 = 4 * np.pi * 1e-7

    Ms = 8.6e5
    A = 16e-12
    D = -3.6e-3
    K = 510e3

    sim = Sim(mesh)

    sim.set_tols(rtol=1e-10, atol=1e-10)

    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = Ms
    sim.do_precession = False

    sim.set_m((0, 0, 1))

    sim.add(UniformExchange(A))
    sim.add(DMI(D, dmi_type='interfacial'))
    sim.add(UniaxialAnisotropy(K, axis=(0, 0, 1)))

    sim.relax(dt=1e-13, stopping_dmdt=0.01, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    m = sim.spin
    return m.copy()

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def test_dw_dmi(mesh=mesh, do_plot=False):

    Ms = 8.0e5
    sim = Sim(mesh, name='relax')

    sim.set_m(m_init_dw)

    sim.driver.set_tols(rtol=1e-8, atol=1e-12)
    sim.Ms = Ms
    sim.alpha = 0.5
    sim.do_precession = False

    A = 1.3e-11
    D = 4e-4
    Kx = 8e4
    Kp = -6e5

    sim.add(UniformExchange(A))
    sim.add(DMI(D))
    sim.add(UniaxialAnisotropy(Kx, axis=[1, 0, 0], name='Kx'))

    sim.driver.relax(stopping_dmdt=0.01)

    xs = np.array([p[0] for p in mesh.coordinates])
    mx, my, mz = analytical(xs, A=A, D=D, K=Kx)
    mxyz = sim.spin.copy()
    mxyz = mxyz.reshape(-1, 3)

    assert max(abs(mxyz[:, 0] - mx)) < 0.002
    assert max(abs(mxyz[:, 1] - my)) < 0.002
    assert max(abs(mxyz[:, 2] - mz)) < 0.0006

    if do_plot:

        save_plot(mxyz, mx, my, mz)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-6, atol=1e-6)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)
    #sim.set_m((0,0.1,1))
    #sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    dmi = DMI(D=1.3e-3)
    sim.add(dmi)

    anis = UniaxialAnisotropy(-3.25e4, axis=(0, 0, 1))
    sim.add(anis)

    zeeman = Zeeman((0, 0, 6.014576e4))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=0.5, max_steps=5000,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def test_energy_dmi(Ms=8e5, D=1.32e-3):

    mesh = CuboidMesh(nx=40, ny=50, nz=1, dx=2.5, dy=2.5, dz=3, unit_length=1e-9)
    sim = Sim(mesh)

    sim.Ms = Ms

    dmi = DMI(D=D, type='interfacial')
    #dmi = DMI(D=D, type='bulk')
    sim.add(dmi)

    def init_m(pos):

        x, y, z = pos

        return (np.sin(x) + y + 2.3 * z, np.cos(x) + y + 1.3 * z, 1)

    sim.set_m(init_m)

    dmi_energy = dmi.compute_energy()

    # init_m0="""
    # return [list [expr {sin($x*1e9)+$y*1e9+$z*2.3e9}] [expr {cos($x*1e9)+$y*1e9+$z*1.3e9}] 1]
    #"""

    #field_oommf = compute_dmi_field(mesh, Ms=Ms, init_m0=init_m0, D=D)

    dmi_energy_oommf = -4.5665527749090378e-20

    print 'dmi energy', dmi_energy

    assert abs(dmi_energy - dmi_energy_oommf) / dmi_energy_oommf < 1e-15

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def test_dmi_field_oommf(D=4.1e-3, Ms=2.6e5):

    mesh = CuboidMesh(nx=10, ny=3, nz=2, dx=0.5, unit_length=1e-9)

    sim = Sim(mesh)
    sim.Ms = Ms

    dmi = DMI(D=D, type='interfacial')
    sim.add(dmi)

    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 = dmi.compute_field()

    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'] ')

    # TODO: check the sign of DMI in OOMMF.
    field_oommf = compute_dmi_field(mesh, Ms=Ms, init_m0=init_m0, D=-D)

    mx0, mx1, mx2 = compare_fields(field_oommf, field)

    assert max([mx0, mx1, mx2]) < 1e-12

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def relax_system(mesh):

    # Only relaxation
    sim = Sim(mesh, name='relax')

    # Simulation parameters
    sim.driver.set_tols(rtol=1e-8, atol=1e-10)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    # The initial state passed as a function
    sim.set_m(init_m)
    # sim.set_m(np.load('m0.npy'))

    # Energies
    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    anis = UniaxialAnisotropy(5e4)
    sim.add(anis)

    # Start relaxation and save the state in m0.npy
    sim.relax(dt=1e-14, stopping_dmdt=0.00001, max_steps=5000,
              save_m_steps=None, save_vtk_steps=None)

    np.save('m0.npy', sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
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

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
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

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def compute_field():

    mesh = CuboidMesh(nx=1, ny=1, nz=1, dx=2.0, dy=2.0, dz=2.0, unit_length=1e-9, periodicity=(True, True, False))

    sim = Sim(mesh, name='relax')

    sim.set_tols(rtol=1e-10, atol=1e-14)
    sim.alpha = 0.5
    sim.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m((0,0,1))
    # sim.set_m(np.load('m0.npy'))

    A = 1.3e-11
    exch = UniformExchange(A=A)
    sim.add(exch)

    demag = Demag(pbc_2d=True)
    sim.add(demag)
    field=demag.compute_field()
    print field

    np.save('m0.npy', sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def relax_system(mesh):

    sim = Sim(mesh, name='relax')

    sim.driver.set_tols(rtol=1e-6, atol=1e-6)
    sim.driver.alpha = 0.5
    sim.driver.gamma = 2.211e5
    sim.Ms = 8.6e5
    sim.do_precession = False

    sim.set_m(init_m)

    exch = UniformExchange(A=1.3e-11)
    sim.add(exch)

    dmi = DMI(D=-4e-3)
    sim.add(dmi)

    zeeman = Zeeman((0, 0, 4e5))
    sim.add(zeeman, save_field=True)

    sim.relax(dt=1e-13, stopping_dmdt=1e-2,
              save_m_steps=None, save_vtk_steps=50)

    np.save('m0.npy', sim.spin)

# 需要导入模块: from fidimag.micro import Sim [as 别名]
# 或者: from fidimag.micro.Sim import Ms [as 别名]
def elongated_part_sim():
    sim = Sim(mesh)
    sim.Ms = lambda r: cylinder(r, centre, 8)
    sim.add(UniformExchange(A=A))
    sim.add(UniaxialAnisotropy(Kx, axis=(0, 1, 0)))  # Anisotropy along y
    sim.add(Demag())

    return sim