code: def grid_angle_to_profile(self, grid_thetas):
          
          theta_coordinate_to_profile = np.add(grid_thetas, - self.phi_radians)
          return np.cos(theta_coordinate_to_profile), np.sin(theta_coordinate_to_profile)
docs: The angle between each angle theta on the grid and the profile, in radians.
  
          Parameters
          -----------
          grid_thetas : ndarray
              The angle theta counter-clockwise from the positive x-axis to each coordinate in radians.