import numpy as np from . import Lattice from . import Rotation class Orientation: # ToDo: make subclass of lattice and Rotation """ Crystallographic orientation. A crystallographic orientation contains a rotation and a lattice. """ __slots__ = ['rotation','lattice'] def __repr__(self): """Report lattice type and orientation.""" return self.lattice.__repr__()+'\n'+self.rotation.__repr__() def __init__(self, rotation, lattice): """ New orientation from rotation and lattice. Parameters ---------- rotation : Rotation Rotation specifying the lattice orientation. lattice : Lattice Lattice type of the crystal. """ if isinstance(lattice, Lattice): self.lattice = lattice else: self.lattice = Lattice(lattice) # assume string if isinstance(rotation, Rotation): self.rotation = rotation else: self.rotation = Rotation.from_quaternion(rotation) # assume quaternion def __getitem__(self,item): """Iterate over leading/leftmost dimension of Orientation array.""" return self.__class__(self.rotation[item],self.lattice) def disorientation(self, other, SST = True, symmetries = False): """ Disorientation between myself and given other orientation. Rotation axis falls into SST if SST == True. Currently requires same symmetry for both orientations. Look into A. Heinz and P. Neumann 1991 for cases with differing sym. """ if self.lattice.symmetry != other.lattice.symmetry: raise NotImplementedError('disorientation between different symmetry classes not supported yet.') mySymEqs = self.equivalent if SST else self.equivalent[0] # take all or only first sym operation otherSymEqs = other.equivalent for i,sA in enumerate(mySymEqs): aInv = sA.rotation.inversed() for j,sB in enumerate(otherSymEqs): b = sB.rotation r = b*aInv for k in range(2): r.inverse() breaker = self.in_FZ \ and (not SST or other.lattice.symmetry.inDisorientationSST(r.as_Rodrigues(vector=True))) if breaker: break if breaker: break if breaker: break return (Orientation(r,self.lattice), i,j, k == 1) if symmetries else r # disorientation ... # ... own sym, other sym, # self-->other: True, self<--other: False def in_FZ(self): """Check if orientations fall into Fundamental Zone.""" return self.lattice.in_FZ(self.rotation.as_Rodrigues(vector=True)) @property def equivalent(self): """ Return orientations which are symmetrically equivalent. One dimension (length according to symmetrically equivalent orientations) is added to the left of the rotation array. """ s = self.lattice.symmetry.symmetry_operations s = s.reshape(s.shape[:1]+(1,)*len(self.rotation.shape)+(4,)) s = Rotation(np.broadcast_to(s,s.shape[:1]+self.rotation.quaternion.shape)) r = np.broadcast_to(self.rotation.quaternion,s.shape[:1]+self.rotation.quaternion.shape) r = Rotation(r) return self.__class__(s@r,self.lattice) def relatedOrientations_vec(self,model): """List of orientations related by the given orientation relationship.""" h = self.lattice.relationOperations(model) rot= h['rotations'] op=np.array([o.as_quaternion() for o in rot]) s = op.reshape(op.shape[:1]+(1,)*len(self.rotation.shape)+(4,)) s = Rotation(np.broadcast_to(s,s.shape[:1]+self.rotation.quaternion.shape)) r = np.broadcast_to(self.rotation.quaternion,s.shape[:1]+self.rotation.quaternion.shape) r = Rotation(r) return self.__class__(s@r,h['lattice']) def relatedOrientations(self,model): """List of orientations related by the given orientation relationship.""" r = self.lattice.relationOperations(model) return [self.__class__(o*self.rotation,r['lattice']) for o in r['rotations']] @property def reduced_vec(self): """Transform orientation to fall into fundamental zone according to symmetry.""" equi= self.equivalent.rotation #equivalent orientations r= 1 if not self.rotation.shape else equi.shape[1] #number of rotations num_equi=equi.shape[0] #number of equivalente orientations quat= np.reshape( equi.as_quaternion(), (r*num_equi,4) ,order='F') #equivalents are listed in intiuitive order boolean=Orientation(quat, self.lattice).in_FZ() #check which ones are in FZ if sum(boolean) == r: return self.__class__(quat[boolean],self.lattice) else: print('More than 1 equivalent orientation has been found for an orientation') index=np.empty(r, dtype=int) for l,h in enumerate(range(0,r*num_equi, num_equi)): index[l]=np.where(boolean[h:h+num_equi])[0][0] + (l*num_equi) #get first index that is true then go check to next orientation return self.__class__(quat[index],self.lattice) def reduced(self): """Transform orientation to fall into fundamental zone according to symmetry.""" for me in self.equivalent: if self.lattice.in_FZ(me.rotation.as_Rodrigues(vector=True)): break return self.__class__(me.rotation,self.lattice) def inversePole(self, axis, proper = False, SST = True): """Axis rotated according to orientation (using crystal symmetry to ensure location falls into SST).""" if SST: # pole requested to be within SST for i,o in enumerate(self.equivalent): # test all symmetric equivalent quaternions pole = o.rotation@axis # align crystal direction to axis if self.lattice.in_SST(pole,proper): break # found SST version else: pole = self.rotation@axis # align crystal direction to axis return (pole,i if SST else 0) def IPF_color(self,axis): #ToDo axis or direction? """TSL color of inverse pole figure for given axis.""" eq = self.equivalent pole = eq.rotation @ np.broadcast_to(axis/np.linalg.norm(axis),eq.rotation.shape+(3,)) in_SST, color = self.lattice.in_SST(pole,color=True) # ignore duplicates (occur for highly symmetric orientations) found = np.zeros_like(in_SST[0],dtype=bool) c = np.empty(color.shape[1:]) for s in range(in_SST.shape[0]): c = np.where(np.expand_dims(np.logical_and(in_SST[s],~found),-1),color[s],c) found = np.logical_or(in_SST[s],found) return c @staticmethod def fromAverage(orientations, weights = []): """Create orientation from average of list of orientations.""" # further read: Orientation distribution analysis in deformed grains # https://doi.org/10.1107/S0021889801003077 if not all(isinstance(item, Orientation) for item in orientations): raise TypeError("Only instances of Orientation can be averaged.") closest = [] ref = orientations[0] for o in orientations: closest.append(o.equivalent[ ref.disorientation(o, SST = False, # select (o[ther]'s) sym orientation symmetries = True)[2]].rotation) # with lowest misorientation return Orientation(Rotation.fromAverage(closest,weights),ref.lattice) def average(self,other): """Calculate the average rotation.""" return Orientation.fromAverage([self,other])