Merge branch 'from_fiber-improvements' into 'development'

From fiber improvements

See merge request damask/DAMASK!573

python/damask/_rotation.py

@@ -1010,7 +1010,7 @@ class Rotation:
     def from_ODF(weights: np.ndarray,
                  phi: np.ndarray,
                  shape: Union[int, IntSequence] = None,
-                 degrees: bool = True,
+                 degrees: bool = False,
                  fractions: bool = True,
                  rng_seed: NumpyRngSeed = None) -> 'Rotation':
         """
@@ -1063,7 +1063,7 @@ class Rotation:
     def from_spherical_component(center: 'Rotation',
                                  sigma: float,
                                  shape: Union[int, IntSequence] = None,
-                                 degrees: bool = True,
+                                 degrees: bool = False,
                                  rng_seed: NumpyRngSeed = None) -> 'Rotation':
         """
         Initialize with samples from a Gaussian distribution around a given center.
@@ -1100,7 +1100,7 @@ class Rotation:
                              sample: IntSequence,
                              sigma: float = 0.0,
                              shape: Union[int, IntSequence] = None,
-                             degrees: bool = True,
+                             degrees: bool = False,
                              rng_seed: NumpyRngSeed = None):
         """
         Initialize with samples from a Gaussian distribution around a given direction.
@@ -1108,9 +1108,11 @@ class Rotation:
         Parameters
         ----------
         crystal : numpy.ndarray, shape (2)
-            Polar coordinates (phi from x, theta from z) of fiber direction in crystal frame.
+            Polar coordinates (polar angle θ from [0 0 1], azimuthal angle φ from [1 0 0])
+            of fiber direction in crystal frame.
         sample : numpy.ndarray, shape (2)
-            Polar coordinates (phi from x, theta from z) of fiber direction in sample frame.
+            Polar coordinates (polar angle θ from z, azimuthal angle φ from x)
+            of fiber direction in sample frame.
         sigma : float, optional
             Standard deviation of (Gaussian) misorientation distribution.
             Defaults to 0.
@@ -1122,13 +1124,39 @@ class Rotation:
             A seed to initialize the BitGenerator.
             Defaults to None, i.e. unpredictable entropy will be pulled from the OS.
 
+        Notes
+        -----
+        The crystal direction for (θ=0,φ=0) is [0 0 1],
+        the sample direction for (θ=0,φ=0) is z.
+
+        Polar coordinates follow the ISO 80000-2:2019 convention
+        typically used in physics.
+        See https://en.wikipedia.org/wiki/Spherical_coordinate_system.
+
+        Ranges 0≤θ≤π and 0≤φ≤2π give a unique set of coordinates.
+
+        Examples
+        --------
+        Create an ideal α-fiber texture (<1 1 0> ǀǀ RD=x) consisting of
+        200 orientations:
+
+        >>> import damask
+        >>> import numpy as np
+        >>> alpha = damask.Rotation.from_fiber_component([np.pi/4.,0.],[np.pi/2.,0.],shape=200)
+
+        Create an ideal γ-fiber texture (<1 1 1> ǀǀ ND=z) consisting of
+        100 orientations:
+
+        >>> import damask
+        >>> gamma = damask.Rotation.from_fiber_component([54.7,45.0],[0.,0.],shape=100,degrees=True)
+
         """
         rng = np.random.default_rng(rng_seed)
-        sigma_,alpha_,beta_ = (np.radians(coordinate) for coordinate in (sigma,crystal,sample)) if degrees else \
+        sigma_,alpha,beta = (np.radians(coordinate) for coordinate in (sigma,crystal,sample)) if degrees else \
                              map(np.array, (sigma,crystal,sample))
 
-        d_cr  = np.array([np.sin(alpha_[0])*np.cos(alpha_[1]), np.sin(alpha_[0])*np.sin(alpha_[1]), np.cos(alpha_[0])])
+        d_cr  = np.array([np.sin(alpha[0])*np.cos(alpha[1]), np.sin(alpha[0])*np.sin(alpha[1]), np.cos(alpha[0])])
-        d_lab = np.array([np.sin( beta_[0])*np.cos( beta_[1]), np.sin( beta_[0])*np.sin( beta_[1]), np.cos( beta_[0])])
+        d_lab = np.array([np.sin( beta[0])*np.cos( beta[1]), np.sin( beta[0])*np.sin( beta[1]), np.cos( beta[0])])
         ax_align = np.append(np.cross(d_lab,d_cr), np.arccos(np.dot(d_lab,d_cr)))
         if np.isclose(ax_align[3],0.0): ax_align[:3] = np.array([1,0,0])
         R_align  = Rotation.from_axis_angle(ax_align if ax_align[3] > 0.0 else -ax_align,normalize=True) # rotate fiber axis from sample to crystal frame

python/tests/test_Orientation.py

@@ -158,6 +158,13 @@ class TestOrientation:
                                                        sigma=0.0,shape=None,rng_seed=0,lattice='cI').quaternion
                    == r.quaternion)
 
+    @pytest.mark.parametrize('crystal,sample,direction,color',[([np.pi/4,0],[np.pi/2,0],[1,0,0],[0,1,0]),
+                                                               ([np.arccos(3**(-.5)),np.pi/4,0],[0,0],[0,0,1],[0,0,1])])
+    def test_fiber_IPF(self,crystal,sample,direction,color):
+        fiber = Orientation.from_fiber_component(crystal=crystal,sample=sample,family='cubic',shape=200)
+        print(np.allclose(fiber.IPF_color(direction),color))
+
+
     @pytest.mark.parametrize('kwargs',[
                                         dict(lattice='aP',a=1.0,b=1.1,c=1.2,alpha=np.pi/4.5,beta=np.pi/3.5,gamma=np.pi/2.5),
                                         dict(lattice='mP',a=1.0,b=1.1,c=1.2,                beta=np.pi/3.5),

python/tests/test_Rotation.py

@@ -1061,7 +1061,7 @@ class TestRotation:
         p = []
         for run in range(5):
             c = Rotation.from_random()
-            o = Rotation.from_spherical_component(c,sigma,shape)
+            o = Rotation.from_spherical_component(c,sigma,shape,degrees=True)
             _, angles = c.misorientation(o).as_axis_angle(pair=True,degrees=True)
             angles[::2] *= -1                                                                       # flip angle for every second to symmetrize distribution
 
@@ -1077,8 +1077,8 @@ class TestRotation:
     def test_from_fiber_component(self,sigma,shape):
         p = []
         for run in range(5):
-            alpha = np.random.random()*2*np.pi,np.arccos(np.random.random())
+            alpha = np.arccos(np.random.random()),np.random.random()*2*np.pi
-            beta  = np.random.random()*2*np.pi,np.arccos(np.random.random())
+            beta  = np.arccos(np.random.random()),np.random.random()*2*np.pi
 
             f_in_C = np.array([np.sin(alpha[0])*np.cos(alpha[1]), np.sin(alpha[0])*np.sin(alpha[1]), np.cos(alpha[0])])
             f_in_S = np.array([np.sin( beta[0])*np.cos( beta[1]), np.sin( beta[0])*np.sin( beta[1]), np.cos( beta[0])])