def minimize(self, max_dpns = 0.01, samples = 10, h_max = 1e-5, h_min = 1e-16):
"""
Minimizes the energy with a direct minimization strategy.
"""
counter = 0
# TODO make use of stephandlers for logging
h = self.state.h
dpnslist = []
log = ScreenLogMinimizer()
# Reset step
self.state.step = 0
while len(dpnslist) < samples or max(dpnslist) > max_dpns:
# Calculate next M and dM for minimization step
M_next = self.state.minimizer_M(h)
dM = self.state.minimizer_dM
counter += 2
# Get s^n-1 for step-size calculation
M_diff = VectorField(self.mesh)
M_diff.assign(M_next)
M_diff.add(self.state.M, -1.0)
# Set next M
self.state.y = M_next
self.state.finish_step() # normalize, TODO really need to do this every step?
self.state.flush_cache()
# Calculate deg per ns
# TODO M.absMax might be the wrong choice if different materials are in use
dp_timestep = (180.0 / math.pi) * math.atan2(M_diff.absMax(), self.state.M.absMax())
dpns = abs(1e-9 * dp_timestep / h)
dpnslist.append(dpns)
if len(dpnslist) > samples: dpnslist.pop(0)
self.state.deg_per_ns_minimizer = dpns
# Get y^n-1 for step-size calculation
dM_diff = VectorField(self.mesh)
dM_diff.assign(self.state.minimizer_dM)
dM_diff.add(dM, -1.0)
# Next stepsize (Alternate h1 and h2)
try:
if (self.state.step % 2 == 0):
h = M_diff.dotSum(M_diff) / M_diff.dotSum(dM_diff)
else:
h = M_diff.dotSum(dM_diff) / dM_diff.dotSum(dM_diff)
except ZeroDivisionError, ex:
h = h_max
h_sign = math.copysign(1, h)
h = max(min(abs(h), h_max), h_min) * h_sign
if (self.state.step % 100 == 0):
log.handle(self.state)
# Update step
self.state.step += 1
def minimize(self, max_dpns = 0.01, samples = 10, h_max = 1e-5, h_min = 1e-16):
"""
Minimizes the energy with a direct minimization strategy.
"""
# TODO make use of stephandlers for logging
h = self.state.h
dpnslist = []
log = ScreenLogMinimizer()
# Reset step
self.state.step = 0
while len(dpnslist) < samples or max(dpnslist) > max_dpns:
# Calculate next M and dM for minimization step
M_next = self.state.minimizer_M(h)
dM = self.state.minimizer_dM
# Get s^n-1 for step-size calculation
M_diff = VectorField(self.mesh)
M_diff.assign(M_next)
M_diff.add(self.state.M, -1.0)
# Set next M
self.state.y = M_next
self.state.finish_step() # normalize, TODO really need to do this every step?
self.state.flush_cache()
# Calculate deg per ns
# TODO M.absMax might be the wrong choice if different materials are in use
dp_timestep = (180.0 / math.pi) * math.atan2(M_diff.absMax(), self.state.M.absMax())
dpns = abs(1e-9 * dp_timestep / h)
dpnslist.append(dpns)
if len(dpnslist) > samples: dpnslist.pop(0)
self.state.deg_per_ns_minimizer = dpns
# Get y^n-1 for step-size calculation
dM_diff = VectorField(self.mesh)
dM_diff.assign(self.state.minimizer_dM)
dM_diff.add(dM, -1.0)
# Next stepsize (Alternate h1 and h2)
try:
if (self.state.step % 2 == 0):
h = M_diff.dotSum(M_diff) / M_diff.dotSum(dM_diff)
else:
h = M_diff.dotSum(dM_diff) / dM_diff.dotSum(dM_diff)
except ZeroDivisionError, ex:
h = h_max
h_sign = math.copysign(1, h)
h = max(min(abs(h), h_max), h_min) * h_sign
if (self.state.step % 100 == 0):
log.handle(self.state)
# Update step
self.state.step += 1
def readOMF(path):
# Read OMF file
header = magneto.OMFHeader()
mat = magneto.readOMF(path, header)
# Convert (header, mat) to VectorField.
mesh = RectangularMesh((header.xnodes, header.ynodes, header.znodes), (header.xstepsize, header.ystepsize, header.zstepsize))
vector_field = VectorField(mesh)
vector_field.assign(mat)
logger.debug("Read file %s", path)
return vector_field
