在ODEINT Python中无法将数组数据从dtype（'complex128'）转换为dtype（'float64'）

Question

在以下使用odeint解决ODE的代码中，我遇到了这样的问题

 od = odeint(OD_H, od0, [z1, z], args=(delt, omgm0, H0,))[-1]
File "C:\Python36-32\lib\site-packages\scipy\integrate\odepack.py", line 244, in odeint
int(bool(tfirst)))
TypeError: Cannot cast array data from dtype('complex128') to dtype('float64') according to the rule 'safe'

代码是：

def OD_H(z, od, delt, omgm0, H0):
    div1 = np.divide(1, (1 + z), where = (1 + z)!= 0)
    a = (1 + z)**(-1)
    M = 1
    B = 3
    Q = 2 * (2 - delt) * (B/(3 * M**2))**(1/(2*(delt-2))) * (H0 * (omgm0)**(0.5))**((1-delt)/(delt-2))
    dMdt = -div1 * od * (1 - od) * (2 * delt - 1 + Q * (1 - od)**((1 - delt)/(2*(2-delt))) * od**(1/(2 *(2-delt))) * exp((3*(1-delt)*np.log(a))/(2*(2-delt))))
    return dMdt

def ant(z, od0, delt, omgm0, H0):
    z1 = 0
    od = odeint(OD_H, od0, [z1, z], args=(delt, omgm0, H0,))[-1]       
    return od     

for z in np.arange(0,3.1,0.1):
    print(ant(z, 0.7, 1.1, 0.3, 67))

我不知道问题是什么。我发现的唯一一件事是关于复杂的值。感谢您对解决方案的帮助。