Bug in probably some gimbal lock prevention code

[ja99]

Hi everyone,

It seems like there is code for preventing gimbal lock, which interferes with valid Euler rotations as well.

Replication

Experiment was performed with Python 3.9 and
ivy-core=1.1.10=pypi_0
ivy-mech=1.1.9=pypi_0

For easier copy/paste, here the code itself:

import numpy as np
import ivy
import ivy_mech
import math
#%%
ivy.set_framework(ivy.numpy)
#%%
rot_order = "zyx"
#%%
in_degree_euler = ivy.array([0, 0, 90])
in_degree_euler
#%%
in_rad_euler = ivy.array([math.radians(x) for x in in_degree_euler])
in_rad_euler
#%%
rot_mat = ivy_mech.euler_to_rot_mat(in_rad_euler, convention=rot_order)
rot_mat
#%%
out_rad_euler = ivy_mech.rot_mat_to_euler(rot_mat, convention=rot_order)
out_rad_euler
#%%
out_degree_euler = ivy.array([math.degrees(x) for x in out_rad_euler])
out_degree_euler

Expected behavior

Thanks,
Janis