ode

如何应用ode

Import commands

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

#prameters
r=0
q=1.1
w=1.2

Derivative function

def derivs(y, t，r，w, q):

输入parameters的值：

# Unpack the current values of the variables we wish to "update" from the y list）
X=y[0]
Y=y[1]

# Right-hand side of odes, which are used to compute the derivative
dXdt = -r*X-w*Y
dYdt =q*X

return dXdt, dYdt

Declare Variables for initial conditions

initial condition
X0=3
Y0=1
y0=[X0, Y0]

define time steps
t=np.linespace(0,20,2000)

sol=odeint(derivs, y0, t, args=(r,w,q))

plt.subplot()/ plt.figure(1)
plt.plot(time,sol[:,0], color=“green”,label="…")
plt.xlabel("…")
plt.ylabel("…")
plt.grid()
plt.legend()