I have discovered an example in which the Jacobian test breaks. I do not see the reason (yet?) why it should not work. ``` import numpy as np import nifty6 as ift dom = ift.UnstructuredDomain(10) op = (1.j*(ift.ScalingOperator(dom, 1.).log()).imag).exp() loc = ift.from_random(op.domain, dtype=np.complex128) + 5 ift.extra.check_jacobian_consistency(op, loc) ``` Note the `+ 5` which shall make sure that the branch cut of the logarithm is avoided.