我想要一个自由落体的物体来“反弹” . 在一个简单的例子中，一个物体从初始高度下降 . 当它击中“地面”时，我希望它“反弹” .

在该示例中，对象以初始速度0下降并且以1g加速 . 有没有办法迫使odeint从'x'位置而不是经过一段时间后终止其“整合”？

或者scipy是否提供了解决问题的更好方法？

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

def gravity (x, t, params):
    # x = (x, x')
    # Ordinary differential equations for displacement and velocity
    # of object in frictionless free-fall.
    g = params
    return [g*t, g]

# First 2 seconds of motion
t = np.arange (0, 2.1, 0.1)
g = -9.8  # m/s^2
bc = np.array ([9.8, 0])
soln = odeint (gravity, bc, t, args = (g,))

# How do we limit odeint to free fall until contact with the ground at x = 0?

fig = plt.figure (1, figsize = (8,8))

ax1 = fig.add_subplot(211)
ax1.plot(t, soln [:,0])
ax1.set_xlabel ('time')
ax1.set_ylabel ('x')

ax1 = fig.add_subplot(212)
ax1.plot(t, soln [:,1])
ax1.set_xlabel ('time')
ax1.set_ylabel ('Vx')

plt.show ()
python scipy odeint