def test_geometric_model_stats():
model = GeometricModel(alpha=4, beta=6)
assert model.pppdf(0) == approx(0)
assert model.pppdf(4) == approx(0.0783216783)
assert model.ppmean() == approx(3)
assert model.ppvar() == approx(3)
def test_geometric_pppdf_x():
model = GeometricModel(alpha=4, beta=6)
assert model.pppdf([-1, 0, 1, 10]) == approx([0, 0, 0.4, 0.0086687306])