  In this paper we study urban segregation of two different communities A and
B, poor and rich, distributed randomly on finite samples, to check cheap and
expensive residences. For this purpose we avoid the complications of the
Schelling model which are not necessary and instead we use the Ising model on
500 x 500 square lattice, which give similar results, with random magnetic
field at lower and higher temperatures (kT/J = 2.0, 99.0) in finite times equal
to 40, 400, 4000 and 40,000. This random-field Ising magnet is a suitable
model, where each site of the square lattice carries a magnetic field h which
is randomly up (expensive) or down (cheap). The resulting addition to the
energy prefers up spins on the expensive and down spins on the cheap sites. Our
simulations were carried out using a 50-lines FORTRAN program. We present at a
lower temperature (2.0) a time series of pictures, separating growing from
non-growing domains. A small random field (h = +- 0.1) allows for large
domains, while a large random field (h = +- 0.9) allows only small clusters. At
higher temperature (99.0) we could not obtain growing domains.
