docstring

Author: j-c-c

src/aspire/abinitio/commonline_utils.py

@@ -273,6 +273,18 @@ def _complete_third_row_to_rot(r3):
 
 
 def _cl_angles_to_ind(cl_angles, n_theta):
+    """
+    Map 2D direction vectors to discretized angular indices.
+
+    For each 2D vector [x, y] in `cl_angles`, compute its polar angle
+    and find the nearest of `n_theta` polar ray indices.
+
+    :param cl_angles: Array of shape (n, 2) of [x, y] values corresponding
+        to the commonline induced by a pair of rotations.
+    :param n_theta: Resolution of polar rays.
+
+    :return: int or array of length n of commonline indice in the range [0, n_theta - 1].
+    """
     thetas = np.arctan2(cl_angles[:, 1], cl_angles[:, 0])
 
     # Shift from [-pi,pi] to [0,2*pi).