def test_int2coord():
with pytest.raises(AssertionError):
hilbert._int2coord(0, 0, 0)
# we always get lower left corner of coding cell
# only one coding cell
assert (-180, -90) == hilbert._int2coord(0, 0, 1)
# lvl 2 is 4 cells: 2 in every direction
assert (-180, -90) == hilbert._int2coord(0, 0, 2)
assert (0, -90) == hilbert._int2coord(1, 0, 2)
assert (-180, 0) == hilbert._int2coord(0, 1, 2)
assert (0, 0) == hilbert._int2coord(1, 1, 2)
def test_coord2int2coord():
for lvl in range(1, 30):
lng_err, lat_err = hilbert._lvl_error(lvl)
dim = 1 << lvl
for _i in range(1000):
lng, lat = rand_lng(), rand_lat()
x, y = hilbert._coord2int(lng, lat, dim)
lng_x, lat_y = hilbert._int2coord(x, y, dim)
# we always get lower left corner of coding cell
# hence add error and then we have +- error
assert lng == pytest.approx(lng_x + lng_err, abs=lng_err)
assert lat == pytest.approx(lat_y + lat_err, abs=lat_err)