def test_conversion2():
    a = 2*list2numpy([x**2, x])
    b = list2numpy([2*x**2, 2*x])
    assert (a == b).all()

    one = Rational(1)
    zero = Rational(0)
    X = list2numpy([one, zero, zero])
    Y = one*X
    X = list2numpy([Symbol("a") + Rational(1, 2)])
    Y = X + X
    assert Y == array([1 + 2*Symbol("a")])
    Y = Y + 1
    assert Y == array([2 + 2*Symbol("a")])
    Y = X - X
    assert Y == array([0])

def test_conversion1():
    a = list2numpy([x**2, x])
    #looks like an array?
    assert isinstance(a, ndarray)
    assert a[0] == x**2
    assert a[1] == x
    assert len(a) == 2

def tonumpy(array,units):
    """ Convert to numpy aa sympy number, a sympy array, or a python array of sympy numbers.

            >>> print tonumpy(units.GeV, units.MeV)
            1000.0
            >>> print tonumpy(tosympy([1],units.GeV),units.MeV)
            [ 1000.]
            >>> print tonumpy([1*units.GeV],units.MeV)
            [ 1000.]
    """
    try:
        if isinstance(array,list):
            return np.asarray([float(i/units) for i in array])
        if hasattr(array,'shape'):
            return sympy.list2numpy(array/units).astype(float)
        else:
            return float(array/units)
    except:
        raise UnitsException("Unable to convert array %s to units %s." % (array,units))

def test_list2numpy():
    assert (array([x**2, x]) == list2numpy([x**2, x])).all()

def test_list2numpy():
    x = Symbol("x")
    assert (array([x**2, x]) == list2numpy([x**2, x])).all()