Python PoissonDistribution示例

示例#1

def test_density():
    x = Symbol('x')
    l = Symbol('l', positive=True)
    rate = Beta(l, 2, 3)
    X = Poisson(x, rate)
    assert isinstance(pspace(X), ProductPSpace)
    assert density(X, Eq(rate, rate.symbol)) == PoissonDistribution(l)

示例#2

def test_Poisson():
    l = 3
    x = Poisson('x', l)
    assert E(x) == l
    assert variance(x) == l
    assert density(x) == PoissonDistribution(l)
    assert isinstance(E(x, evaluate=False), Sum)
    assert isinstance(E(2 * x, evaluate=False), Sum)

示例#3

def test_PoissonDistribution():
    l = 3
    p = PoissonDistribution(l)
    assert abs(p.cdf(10).evalf() - 1) < .001
    assert p.expectation(x, x) == l
    assert p.expectation(x**2, x) - p.expectation(x, x)**2 == l

示例#4

文件： test_discrete_rv.py 项目： skirpichev/diofant

def test_PoissonDistribution():
    l = 3
    p = PoissonDistribution(l)
    assert abs(p.cdf(10).evalf() - 1) < .001
    assert p.expectation(x, x) == l
    assert p.expectation(x**2, x) - p.expectation(x, x)**2 == l