odepack.error: Extra arguments must be in a tuple

Question

我的 ode 求解器有一些问题，我正在尝试解决 SEIR 问题，尽管我的代码基于非常相似的代码，但我不断遇到相同的错误。我的代码是：

import numpy as np
from scipy.integrate import odeint
import matplotlib.pyplot as plt

# Total population, N.
N1 = 55600
# Initial number of infected and recovered individuals, I0 and R0.
I10, R10, E10 = 1, 0, 0
# Everyone else, S0, is susceptible to infection initially.
S10 = N1 - I10 - R10 - E10
# parameters
B = 0.05
a = 0.000001
d = 0.0167
g = 0.0167
z = 0.0167
M = 100000

# A grid of time points (in months)
t = np.linspace(0, 160, 160)

# The SIR model differential equations.
def deriv(y, t, N1, B, a, d, g, z, M):
S1, E1, I1, R1 = y

dS1dt = B*N1 + d*(R1) - S1/N1 * (M*a(I1))
dE1dt = S1/N1 * M*a(I1) - g * E1
dI1dt = g * E1 - z * I1
dR1dt = z * I1 - d * R1

return dS1dt, dE1dt, dI1dt, dR1dt

# Initial conditions vector
y0 = S10, E10, I10, R10
# Integrate the SIR equations over the time grid, t.
ret = odeint(deriv, y0, t, args=[N1, B, a, d, g, z, M])
S1, E1, I1, R1 = ret.T

我不断收到错误消息：

文件 "C:/Users/Angus/PycharmProjects/firstAttempt/bugfinder.py"，第 44 行，在

  ret = odeint(deriv, y0, t, args=[N1, B, a, d, g, z, M],)

文件 "C:\Python36\lib\site-packages\scipy\integrate\odepack.py"，第 215 行，在 odeint 中 ixpr、mxstep、mxhnil、mxordn、mxords） odepack.error: 额外的参数必须在元组中

如有任何帮助，我们将不胜感激！

Answer 1

尝试替换：

  ret = odeint(deriv, y0, t, args=[N1, B, a, d, g, z, M],)

有了这个：

  ret = odeint(deriv, y0, t, args=(N1, B, a, d, g, z, M))

来自scipy documentation:

args : tuple, optional

Extra arguments to pass to function.

此外，google differences b/w list and tuple。

Answer 2

对于单个参数，不要忘记在元组中添加逗号，例如

    ret = odeint(deriv, y0, t, args=(singleArg,))

请参阅此处 https://www.tutorialspoint.com/python/python_tuples.htm 了解单值元组。

很遗憾，我没有足够的声誉来发表评论。

odepack.error: Extra arguments must be in a tuple

odepack.error: Extra arguments must be in a tuple

python

ode

pycharm