yapf

logger = logging.getLogger(__name__)

def unit_vector(vector):

  """ Returns the unit vector of the vector.  """

  return vector / np.linalg.norm(vector)

def angle_between(vector_i, vector_j):

  """Returns the angle in radians between vectors "vector_i" and "vector_j"::

      return np.pi

  return angle

def generate_random_unit_vector():

  """Generate a random unit vector on the sphere S^2.

       np.sqrt(1 - z**2) * np.sin(theta), z])

  return (u)

def generate_random_rotation_matrix():

  """Generates a random rotation matrix.

  R = np.column_stack((u, vp, w))

  return (R)

def is_angle_within_cutoff(vector_i, vector_j, angle_cutoff):

  """A utility function to compute whether two vectors are within a cutoff from 180 degrees apart. 

    The deviation from 180 (in degrees)

  """

  angle = angle_between(vector_i, vector_j) * 180. / np.pi

  return (angle > (180 - angle_cutoff) and

          angle < (180. + angle_cutoff))

  return (angle > (180 - angle_cutoff) and angle < (180. + angle_cutoff))

from deepchem.utils.geometry_utils import generate_random_rotation_matrix

from deepchem.utils.geometry_utils import is_angle_within_cutoff

class TestGeometryUtils(unittest.TestCase):

  def test_generate_random_unit_vector(self):