}
""")
mag.set_local_magnetic_coupling(mat_Dy, mat_Fe, -80.0)
mag.defregion("DyFe2", nm.box([1.0], [2.0]), mag_mat=[mat_Dy, mat_Fe])
mag.defregion(
"YFe2",
nm.union([nm.box([0.0], [1.0]), nm.box([2.0], [3.0])]),
mag_mat=mat_Fe # can pass either a material or a list of materials
)
mag.set_meshing_parameters(
cache_name="exchange-spring-mesh",
bounding_box=([-1.0], [5.0]),
a0=0.25,
max_steps=100,
)
mag.create_mesh()
def initial_m(dof_name, coords):
print "DDD initial_M(dof_name=\"", dof_name, "\",coords=", coords, ")\n"
dir = dof_name[1][0]
if dir == 0:
return 0.0
elif dir == 1:
return math.cos(2.0 * math.pi * coords[0] / 6.0)
else:
return math.sin(2.0 * math.pi * coords[0] / 6.0)
)
mag.set_local_magnetic_coupling(mat_Dy,mat_Fe,-80.0)
mag.defregion("DyFe2",nm.box([1.0],[2.0]),
mag_mat=[mat_Dy,mat_Fe]
)
mag.defregion("YFe2", nm.union([nm.box([0.0],[1.0]),nm.box([2.0],[3.0])]),
mag_mat=mat_Fe # can pass either a material or a list of materials
)
mag.set_meshing_parameters(cache_name="exchange-spring-mesh",
bounding_box=([-1.0],[5.0]),
a0=0.25,
max_steps=100,
)
mag.create_mesh()
def initial_m(dof_name,coords):
print "DDD initial_M(dof_name=\"",dof_name,"\",coords=",coords,")\n"
dir=dof_name[1][0]
if dir==0:
return 0.0
elif dir==1:
return math.cos(2.0*math.pi*coords[0]/6.0)
else:
return math.sin(2.0*math.pi*coords[0]/6.0)
mag.set_intensive_parameters([])
# mag.set_default_order(1) # default anyway...
mag.set_features({"demag":True,"exchange":True,"timestep":True}) # XXX change usage!
mat_Py = mag.MagMaterial("Py",Ms=1.0,A=13.0, # A = exchange constant
)
mag.defregion("Py", nm.ellipsoid([3.0,3.0,3.0]), mag_mat=mat_Py)
mag.set_meshing_parameters(cache_name="exchange-spring-mesh",
bounding_box=([-4.0,-4.0,-4.0],[4.0,4.0,4.0]),
a0=1.0,
max_steps=600,
)
mag.create_mesh()
mag.set_magnetization([0.0,0.0,1.0]) # providing a vector rather than a function
import nfem.visual
nfem.visual.fields2vtkfile([mag.default_simulation_context.field_M],'sphere-initial.vtk',mesh=mag.default_simulation_context.mesh)
mag.advance_time_cvode(0.02)
nfem.visual.fields2vtkfile([mag.default_simulation_context.field_M],'sphere-final.vtk',mesh=mag.default_simulation_context.mesh)
"Ball 2",
nm.ellipsoid([2.0, 2.0, 2.0], transform=[("shift", [3.0, 0.0, 0.0])]))
# Note: clearly, we DO need a better way to specify geometries. Ideally, I would like to be
# able to write instead:
#
# mag.defregion("Ball 1",nm.shifted([-3,0,0],nm.sphere(3)))
# mag.defregion("Ball 2",nm.shifted([ 3,0,0],nm.sphere(3)))
#
# or alternatively:
#
# sphere = nm.sphere(3)
# mag.defregion("Ball 1",nm.shifted([-3,0,0],sphere))
# mag.defregion("Ball 2",nm.shifted([ 3,0,0],sphere))
mag.set_meshing_parameters(cache_name="two-balls")
mag.create_mesh()
def initial_M(dof_name, coords):
dir = dof_name[1][0]
if dir == 0:
return math.cos(coords[0])
elif dir == 1:
return math.sin(coords[0])
else:
return 0
mag.set_magnetization([1.0, 0.0, 0.0]) # may also provide a function here!
mag.defregion("Ball 2",nm.ellipsoid([2.0,2.0,2.0],transform=[("shift",[3.0,0.0,0.0])]))
# Note: clearly, we DO need a better way to specify geometries. Ideally, I would like to be
# able to write instead:
#
# mag.defregion("Ball 1",nm.shifted([-3,0,0],nm.sphere(3)))
# mag.defregion("Ball 2",nm.shifted([ 3,0,0],nm.sphere(3)))
#
# or alternatively:
#
# sphere = nm.sphere(3)
# mag.defregion("Ball 1",nm.shifted([-3,0,0],sphere))
# mag.defregion("Ball 2",nm.shifted([ 3,0,0],sphere))
mag.set_meshing_parameters(cache_name="two-balls")
mag.create_mesh()
def initial_M(dof_name,coords):
dir=dof_name[1][0]
if dir==0:
return math.cos(coords[0])
elif dir==1:
return math.sin(coords[0])
else: return 0
mag.set_magnetization([1.0,0.0,0.0]) # may also provide a function here!
#mag.set_magnetization(initial_M) # may also provide a function here!