test_integrals.py 文件源码

def test_issue_4892a():
    A, z = symbols('A z')
    c = Symbol('c', nonzero=True)
    P1 = -A*exp(-z)
    P2 = -A/(c*t)*(sin(x)**2 + cos(y)**2)

    h1 = -sin(x)**2 - cos(y)**2
    h2 = -sin(x)**2 + sin(y)**2 - 1

    # there is still some non-deterministic behavior in integrate
    # or trigsimp which permits one of the following
    assert integrate(c*(P2 - P1), t) in [
        c*(-A*(-h1)*log(c*t)/c + A*t*exp(-z)),
        c*(-A*(-h2)*log(c*t)/c + A*t*exp(-z)),
        c*( A* h1 *log(c*t)/c + A*t*exp(-z)),
        c*( A* h2 *log(c*t)/c + A*t*exp(-z)),
        (A*c*t - A*(-h1)*log(t)*exp(z))*exp(-z),
        (A*c*t - A*(-h2)*log(t)*exp(z))*exp(-z),
    ]