  In spin based quantum dot arrays, material or fabrication imprecisions affect
the behaviour of the device, which must be taken into account when controlling
it. This requires measuring the shape of specific convex polytopes. In this
work, we present an algorithm that automatically discovers count, shape and
size of the facets of a convex polytope from measurements. Results on simulated
devices as well as a real 2x2 spin qubit array show that we can reliably find
the facets of the convex polytopes, including small facets with sizes on the
order of the measurement precision.
