which returns the following error: TypeError: in method 'Transform_TransformVector', argument 2 of type 'std::vector< double,std::allocator< double > > const &'

Clearly I am specifying the inputs wrongly but I haven’t found any example of apply this function in the documentation or forum. Please help!

Per the function documentation, for linear transforms such as Euler3D the point does not matter, so any arbitrary setting is fine:

import SimpleITK as sitk
import numpy as np
transform = sitk.Euler3DTransform()
transform.SetTranslation([10, 20, 30])
transform.SetRotation(0, 0, np.pi/2.0) #90 degree rotation around z, x axis should become y
v = [1, 0, 0] # x axis
arbitrary_p = [0, 0, 0]
print(transform.TransformVector(v, arbitrary_p))