  Due to the lack of simulation tools that take into account the actual
geometry of complicated quantum Hall samples there are lots of experiments that
are not yet fully understood. Already some years ago R. G. Mani recorded a
shift of the Hall resistance transitions to lower magnetic fields in samples of
a Hall bar with embedded anti-Hall bar by using partial gating. We use a
Nonequilibrium Network Model (NNM) to simulate this geometry and find
qualitative agreement. Fitting the simulated resistance curves to the
experimental results we can not only determine the carrier concentration but
also obtain an estimate of the screened gating potential and especially the
amplitude and lengthscale of potential fluctuations from charge inhomogenities
which are not easily accessible by experiment.
