diff options
Diffstat (limited to 'sample.py')
| -rw-r--r-- | sample.py | 27 |
1 files changed, 27 insertions, 0 deletions
@@ -1,4 +1,5 @@ import numpy as np +from transform import rotate def uniform_sphere(size=None, dtype=np.double): """ @@ -27,3 +28,29 @@ def uniform_sphere(size=None, dtype=np.double): points[:,2] = u return points + +def flashlight(phi=np.pi/4, direction=(0,0,1), size=None, dtype=np.double): + theta, u = np.random.uniform(0.0, 2*np.pi, size), \ + np.random.uniform(np.cos(phi), 1, size) + + c = np.sqrt(1-u**2) + + if np.equal(direction, (0,0,1)).all(): + rotation_axis = (0,0,1) + rotation_angle = 0.0 + else: + rotation_axis = np.cross((0,0,1), direction) + rotation_angle = \ + -np.arccos(np.dot(direction, (0,0,1))/np.linalg.norm(direction)) + + if size is None: + return rotate(np.array([c*np.cos(theta), c*np.sin(theta), u]), + rotation_angle, rotation_axis) + + points = np.empty((size, 3), dtype) + + points[:,0] = c*np.cos(theta) + points[:,1] = c*np.sin(theta) + points[:,2] = u + + return rotate(points, rotation_angle, rotation_axis) |