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 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.equivalentOrientations() if SST else self.equivalentOrientations([0]) # take all or only first sym operation otherSymEqs = other.equivalentOrientations() 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.lattice.symmetry.inFZ(r.as_Rodrigues(vector=True)) \ 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 inFZ_vec(self): """Check if orientations fall into Fundamental Zone.""" if not self.rotation.shape: return self.lattice.symmetry.inFZ(self.rotation.as_Rodrigues(vector=True)) else: return [self.lattice.symmetry.inFZ(\ self.rotation.as_Rodrigues(vector=True)[l]) for l in range(self.rotation.shape[0])] def inFZ(self): return self.lattice.symmetry.inFZ(self.rotation.as_Rodrigues(vector=True)) @property def equivalent_vec(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 #24 lines (sym) x 4 columns (quat) s = s.reshape(s.shape[:1]+(1,)*len(self.rotation.shape)+(4,)) #reshape zo (24,1,4) 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) #(24,NumRots,4) r = Rotation(r) #(24, NumRot) return self.__class__(s@r,self.lattice) def equivalentOrientations(self,members=[]): """List of orientations which are symmetrically equivalent.""" try: iter(members) # asking for (even empty) list of members? except TypeError: return self.__class__(self.lattice.symmetry.symmetryOperations(members)*self.rotation,self.lattice) # no, return rotation object else: return [self.__class__(q*self.rotation,self.lattice) \ for q in self.lattice.symmetry.symmetryOperations(members)] # yes, return list of rotations 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_vec.rotation #24 x rot x 3(rodrigues vector) r= 1 if not self.rotation.shape else equi.shape[1] #number of rotations quat=np.empty( [r , 4]) for rot in range(r): for sym in range(equi.shape[0]): if self.lattice.symmetry.inFZ(equi.as_Rodrigues(vector=True)[sym,rot]): quat[rot]=equi.as_quaternion()[sym,rot] break return self.__class__(quat,self.lattice) def reduced(self): """Transform orientation to fall into fundamental zone according to symmetry.""" for me in self.equivalentOrientations(): if self.lattice.symmetry.inFZ(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.equivalentOrientations()): # test all symmetric equivalent quaternions pole = o.rotation@axis # align crystal direction to axis if self.lattice.symmetry.inSST(pole,proper): break # found SST version else: pole = self.rotation@axis # align crystal direction to axis return (pole,i if SST else 0) def IPFcolor(self,axis): """TSL color of inverse pole figure for given axis.""" color = np.zeros(3,'d') for o in self.equivalentOrientations(): pole = o.rotation@axis # align crystal direction to axis inSST,color = self.lattice.symmetry.inSST(pole,color=True) if inSST: break return color def IPFcolor_vec(self,axis): """TSL color of inverse pole figure for given axis. Not for hex or triclinic lattices.""" eq = self.equivalent_vec pole = eq.rotation @ np.broadcast_to(axis/np.linalg.norm(axis),eq.rotation.shape+(3,)) in_SST, color = self.lattice.symmetry.in_SST(pole,color=True) # ignore duplicates (occur for highly symmetric orientations) found = np.zeros_like(in_SST[1],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.equivalentOrientations( 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])