我只是得到一个球直接向上,我能改变什么

Question

import numpy as np
import  matplotlib.pyplot as plot
from IPython.display import HTML
from matplotlib import animation
#setup fig with axis
fig, ax = plot.subplots(figsize=(8,8))
#set axis limits
ax.set(xlim=(-2,2), ylim=(0,600), xlabel="position, metres", ylabel="height, metres", title="falling apple")
#initial params
T = 100.
m = 3
g = 9.81
v0x = 10
H = 553.
#setting calc interval
dt = 0.1
N = int(T/dt)
#arrays 
v = np.zeros((N+1 , 2))
x = np.zeros((N+1 , 2))
f = np.zeros((N+1 , 2))
#array start [x ,y] format
v[0] = np.array([0. , H])
x[0] = np.array([v0x , 0.])
# the only force is gravity
f[:] = np.array([0., m * g])
#running the dynamics sim
for n in range(N):
v[n+1] = v[n] + ((f[n]/m) * dt)
x[n+1] = x[n] + (v[n+1] * dt)
#scatter plot
scat_plt = ax.scatter(x[0,0], x[0,1], marker='o', c='#1f77b4', s=200)
## animating 
def animate(i):
scat_plt.set_offsets(x[i])
ani = animation.FuncAnimation(fig, func=animate, frames=N)
ani.save('ball.html', writer=animation.HTMLWriter(fps= 1//dt))
plot.close()
ani.save('ball.mp4', fps= 1//dt)
HTML('ball.html')

输出只是一个直线上升的圆圈，因为这应该模拟一个球从塔上水平抛出

如果有人能建议对逻辑/物理或代码进行任何更改，将不胜感激。

谢谢! !

Answer 1

我想你把x和v混在一起了。y中的力也应该是负的。我试过这个，它似乎工作:

import numpy as np
import  matplotlib.pyplot as plot
from IPython.display import HTML
from matplotlib import animation
#setup fig with axis
fig, ax = plot.subplots(figsize=(8,8))
#set axis limits
ax.set(xlim=(-200,200), ylim=(0,600), xlabel="position, metres", ylabel="height, metres", title="falling apple")
#initial params
T = 100.
m = 3
g = 9.81
v0x = 10
H = 553.
#setting calc interval
dt = 0.1
N = int(T/dt)
#arrays 
v = np.zeros((N+1 , 2))
x = np.zeros((N+1 , 2))
f = np.zeros((N+1 , 2))
#array start [x ,y] format
x[0] = np.array([0. , H])
v[0] = np.array([v0x , 0.])
# the only force is gravity
f[:] = np.array([0., -m * g])
#running the dynamics sim
for n in range(N):
v[n+1] = v[n] + ((f[n]/m) * dt)
x[n+1] = x[n] + (v[n+1] * dt)
#scatter plot
scat_plt = ax.scatter(x[0,0], x[0,1], marker='o', c='#1f77b4', s=200)
## animating 
def animate(i):
scat_plt.set_offsets(x[i])
ani = animation.FuncAnimation(fig, func=animate, frames=N)
ani.save('ball.html', writer=animation.HTMLWriter(fps= 1//dt))
plot.close()
ani.save('ball.gif', fps= 1//dt)
HTML('ball.html')