Hello everyone:

May I ask for your help so I may better understand pygplates.RotationModel.get_rotation()?

From what I understand, when I find the relative stage pole and the angle of rotation of plate A relative to plate B from time_1 to time_2, I should have the same value for the stage pole and the same magnitude (different sign) for the angle of rotation of plate B relative to plate A from time_1 to time_2.

However, the result I got from the pygplates.RotationModel.get_rotation() is not quite what I expected. I used pygplates.RotationModel.get_rotation() function to write a function named ‘*find_finite_rotation_pole_for_a_pair_of_GDUs(rotation_model, moving_plate_id, fixed_plate_id, reconstruction_time, interval, reference_frame)*’.

Below is the result when I tried to find the stage rotation pole of 10752 relative to 10911 and vice versa with the same time and the same reference frame:

fixed_plate_id

10752

moving_plate_id

10911

Euler_pole,angle_rads

(0.621123, 0.703395, 0.345605) -0.003916917173304894

lat,lon,angle_degrees

20.218719836272662 48.55434933895832 -0.22442282273268285

fixed_plate_id

10911

moving_plate_id

10752

Euler_pole,angle_rads

(-0.280809, 0.516842, 0.808715) 0.003916917173304894

lat,lon,angle_degrees

53.97058598010591 118.51598731086054 0.22442282273268285

The magnitude of the rotation angle is the same; however, the coordinates of the pole are different.

Will you please help me better understand this issue?

Best,