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DAMASK_EICMD
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restored orientation averaging capability

This commit is contained in:
Philip Eisenlohr 2019-04-11 17:18:32 -04:00
parent 598e8034b4
commit b8285d5749
1 changed files with 59 additions and 43 deletions
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98
python/damask/orientation.py
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@ -35,14 +35,6 @@ class Quaternion:
"""Components"""
return iter(self.asList())
def asArray(self):
"""As numpy array"""
return np.array((self.q,self.p[0],self.p[1],self.p[2]))
def asList(self):
return [self.q]+list(self.p)
def __repr__(self):
"""Readable string"""
return 'Quaternion: (real={q:+.6f}, imag=<{p[0]:+.6f}, {p[1]:+.6f}, {p[2]:+.6f}>)'.format(q=self.q,p=self.p)
@ -180,6 +172,17 @@ class Quaternion:
return not self.__eq__(other)
def asM(self):
"""Intermediate representation useful for quaternion averaging (see F. Landis Markley et al.)"""
return np.outer(self.asArray(),self.asArray())
def asArray(self):
"""As numpy array"""
return np.array((self.q,self.p[0],self.p[1],self.p[2]))
def asList(self):
return [self.q]+list(self.p)
def normalize(self):
d = self.magnitude()
if d > 0.0:
@ -294,6 +297,10 @@ class Rotation:
def asCubochoric(self):
return qu2cu(self.quaternion.asArray())
def asM(self):
"""Intermediate representation useful fro quaternion averaging (see F. Landis Markley et al.)"""
return self.quaternion.asM()
################################################################################################
# static constructors. The input data needs to follow the convention, options allow to
@ -503,7 +510,7 @@ class Symmetry:
otherOrder = Symmetry.lattices.index(other.lattice)
return (myOrder > otherOrder) - (myOrder < otherOrder)
def symmetryOperations(self):
def symmetryOperations(self,who=[]):
"""List of symmetry operations as quaternions."""
if self.lattice == 'cubic':
symQuats = [
@ -570,7 +577,8 @@ class Symmetry:
[ 1.0,0.0,0.0,0.0 ],
]
return [Rotation(q) for q in symQuats]
return list(map(Rotation,
np.array(symQuats)[np.atleast_1d(np.array(who)) if who != [] else range(len(symQuats))]))
def inFZ(self,R):
@ -579,6 +587,8 @@ class Symmetry:
Fundamental zone in Rodrigues space is point symmetric around origin.
"""
if np.any(R == np.inf): return False
Rabs = abs(R[0:3]*R[3])
if self.lattice == 'cubic':
@ -1050,7 +1060,8 @@ class Orientation:
def disorientation(self,
other,
SST = True):
SST = True,
symmetries = False):
"""
Disorientation between myself and given other orientation.
@ -1076,15 +1087,18 @@ class Orientation:
if breaker: break
if breaker: break
return r
return (r, i,j, k == 1) if symmetries else r # disorientation ...
# ... own sym, other sym,
# self-->other: True, self<--other: False
def inFZ(self):
return self.lattice.symmetry.inFZ(self.rotation.asRodrigues())
def equivalentOrientations(self):
def equivalentOrientations(self, who=[]):
"""List of orientations which are symmetrically equivalent"""
return [self.__class__(q*self.rotation,self.lattice) \
for q in self.lattice.symmetry.symmetryOperations()]
for q in self.lattice.symmetry.symmetryOperations(who)]
def relatedOrientations(self,model):
"""List of orientations related by the given orientation relationship"""
@ -1125,37 +1139,39 @@ class Orientation:
return color
# @classmethod
# def average(cls,
# orientations,
# multiplicity = []):
# """
# Average orientation
@classmethod
def average(cls,
orientations,
multiplicity = []):
"""
Average orientation
# ref: F. Landis Markley, Yang Cheng, John Lucas Crassidis, and Yaakov Oshman.
# Averaging Quaternions,
# Journal of Guidance, Control, and Dynamics, Vol. 30, No. 4 (2007), pp. 1193-1197.
# doi: 10.2514/1.28949
# usage:
# a = Orientation(Eulers=np.radians([10, 10, 0]), symmetry='hexagonal')
# b = Orientation(Eulers=np.radians([20, 0, 0]), symmetry='hexagonal')
# avg = Orientation.average([a,b])
# """
# if not all(isinstance(item, Orientation) for item in orientations):
# raise TypeError("Only instances of Orientation can be averaged.")
ref: F. Landis Markley, Yang Cheng, John Lucas Crassidis, and Yaakov Oshman.
Averaging Quaternions,
Journal of Guidance, Control, and Dynamics, Vol. 30, No. 4 (2007), pp. 1193-1197.
doi: 10.2514/1.28949
usage:
a = Orientation(Eulers=np.radians([10, 10, 0]), symmetry='hexagonal')
b = Orientation(Eulers=np.radians([20, 0, 0]), symmetry='hexagonal')
avg = Orientation.average([a,b])
"""
if not all(isinstance(item, Orientation) for item in orientations):
print('got a list of {}'.format(orientations))
raise TypeError("Only instances of Orientation can be averaged.")
# N = len(orientations)
# if multiplicity == [] or not multiplicity:
# multiplicity = np.ones(N,dtype='i')
N = len(orientations)
if multiplicity == [] or not multiplicity:
multiplicity = np.ones(N,dtype='i')
# reference = orientations[0] # take first as reference
# for i,(o,n) in enumerate(zip(orientations,multiplicity)):
# closest = o.equivalentOrientations(reference.disorientation(o,SST = False)[2])[0] # select sym orientation with lowest misorientation
# M = closest.quaternion.asM() * n if i == 0 else M + closest.quaternion.asM() * n # noqa add (multiples) of this orientation to average noqa
# eig, vec = np.linalg.eig(M/N)
ref = orientations[0] # take first as reference
for i,(o,n) in enumerate(zip(orientations,multiplicity)):
closest = o.equivalentOrientations(ref.disorientation(o,SST=False,symmetries=True)[2])[0] # select sym orientation with lowest misorientation
M = closest.rotation.asM() * n if i == 0 \
else M + closest.rotation.asM() * n # noqa add (multiples) of this orientation to average noqa
eig, vec = np.linalg.eig(M/N)
# return Orientation(quaternion = Quaternion(quat = np.real(vec.T[eig.argmax()])),
# symmetry = reference.symmetry.lattice)
return Orientation(Rotation.fromQuaternion(np.real(vec.T[eig.argmax()]),acceptHomomorph = True),
ref.lattice)
####################################################################################################