我之前非常差劲地问过这个问题，所以我将尝试更详细一些。
我已经制作了一些行星轨道程序，我想知道是否可以将人物围绕改变位置的艺术家居中，以便人物窗口移动而不是停留在（0,0）
因此，如果在simData中定义艺术家的中心，如下所示：
planet1.center = x1,y1
我认为某处必须是这样的：
ax = plt.axes(xlim=(x1-430000000, x1+430000000), ylim=(y1-430000000, y1+430000000))
我无法执行这些操作，因为我无法调出这些变量。另外，轴和图形仅在程序开始时定义一次。
这是我的代码，有4个行星在轨道运动：
import numpy as np
import matplotlib.pyplot as plt
import math
import matplotlib.animation as animation
import pdb
er = 6378100#m
mr = 1737400#m
sr = 696000000
em = 2*5.97219*10**24#kg
mm = 7.34767309*10**22#kg
sm = 1.989*10**30
sed = 150000000000
emd = 384400000
m1 = em
m2 = mm*4
m3 = mm*2
m4 = mm*3
r1 = mr*10*6
r2 = mr*10*3
r3 = mr*10*1.2
r4 = mr*10*2
nts = 10000
ts = 10000
G = 6.67384*10**(-11)
def simData():
tmax = ts*nts
t = 0
x = 0
x1 = 384400000*0.8*0
y1 = 384400000*0.8*0
x2 = 384400000*0.8
y2 = -384400000*0.8*0
x3 = -384400000*0.8
y3 = 384400000*0.8*0
x4 = -384400000*0.8*0
y4 = -384400000*0.8
Vx1 = 0
Vy1 = 0
Vx2 = 800
Vy2 = 1700
Vx3 = 0
Vy3 = -1500
Vx4 = 2000
Vy4 = 0
d12 = math.sqrt((x1-x2)**2+(y1-y2)**2)
d23 = math.sqrt((x2-x3)**2+(y2-y3)**2)
d13 = math.sqrt((x1-x3)**2+(y1-y3)**2)
d14 = math.sqrt((x1-x4)**2+(y1-y4)**2)
d24 = math.sqrt((x2-x4)**2+(y2-y4)**2)
d34 = math.sqrt((x3-x4)**2+(y3-y4)**2)
while t < tmax:
Fg12 = G*(m1*m2)/d12**2
Fgx12 = -Fg12*((x1-x2))/d12
Fgy12 = -Fg12*((y1-y2))/d12
Fgx21 = -Fg12*((x2-x1))/d12
Fgy21 = -Fg12*((y2-y1))/d12
Fg13 = G*(m1*m3)/d13**2
Fgx13 = -Fg13*((x1-x3))/d13
Fgy13 = -Fg13*((y1-y3))/d13
Fgx31 = -Fg13*((x3-x1))/d13
Fgy31 = -Fg13*((y3-y1))/d13
Fg23 = G*(m3*m2)/d23**2
Fgx23 = -Fg23*((x2-x3))/d23
Fgy23 = -Fg23*((y2-y3))/d23
Fgx32 = -Fg23*((x3-x2))/d23
Fgy32 = -Fg23*((y3-y2))/d23
Fg14 = G*(m1*m4)/d14**2
Fgx14 = -Fg14*((x1-x4))/d14
Fgy14 = -Fg14*((y1-y4))/d14
Fgx41 = -Fg14*((x4-x1))/d14
Fgy41 = -Fg14*((y4-y1))/d14
Fg24 = G*(m2*m4)/d24**2
Fgx24 = -Fg24*((x2-x4))/d24
Fgy24 = -Fg24*((y2-y4))/d24
Fgx42 = -Fg24*((x4-x2))/d24
Fgy42 = -Fg24*((x4-x2))/d24
Fg34 = G*(m3*m4)/d34**2
Fgx34 = -Fg34*((x3-x4))/d34
Fgy34 = -Fg34*((y3-y4))/d34
Fgx43 = -Fg34*((x4-x3))/d34
Fgy43 = -Fg34*((y4-y3))/d34
Ax1 = Fgx12/m1 + Fgx13/m1 + Fgx14/m1
Ay1 = Fgy12/m1 + Fgy13/m1 + Fgy14/m1
Ax2 = Fgx21/m2 + Fgx23/m2 + Fgx24/m2
Ay2 = Fgy21/m2 + Fgy23/m2 + Fgy24/m2
Ax3 = Fgx32/m3 + Fgx31/m3 + Fgx34/m3
Ay3 = Fgy32/m3 + Fgy31/m3 + Fgy34/m3
Ax4 = Fgx41/m4 + Fgx42/m4 + Fgx43/m4
Ay4 = Fgy41/m4 + Fgy42/m4 + Fgx43/m4
Vx1 = Vx1+Ax1*ts
Vy1 = Vy1+Ay1*ts
Vx2 = Vx2+Ax2*ts
Vy2 = Vy2+Ay2*ts
Vx3 = Vx3+Ax3*ts
Vy3 = Vy3+Ay3*ts
Vx4 = Vx4+Ax4*ts
Vy4 = Vy4+Ay4*ts
x1 = x1 + Vx1*ts
y1 = y1 + Vy1*ts
x2 = x2 + Vx2*ts
y2 = y2 + Vy2*ts
x3 = x3 + Vx3*ts
y3 = y3 + Vy3*ts
x4 = x4 + Vx4*ts
y4 = y4 + Vy4*ts
planet1.center = x1,y1
planet2.center = x2,y2
planet3.center = x3,y3
planet4.center = x4,y4
d12 = math.sqrt((x1-x2)**2+(y1-y2)**2)
d23 = math.sqrt((x2-x3)**2+(y2-y3)**2)
d13 = math.sqrt((x1-x3)**2+(y1-y3)**2)
d14 = math.sqrt((x1-x4)**2+(y1-y4)**2)
d24 = math.sqrt((x2-x4)**2+(y2-y4)**2)
d34 = math.sqrt((x3-x4)**2+(y3-y4)**2)
t = t+ts
yield x, t
def simPoints(simData):
x, t = simData[0], simData[1]
time_text.set_text(time_template%(t))
line.set_data(t, x)
return line, time_text
fig = plt.figure()
ax = plt.axes(xlim=(-430000000, 430000000), ylim=(-430000000, 430000000))
ax.set_aspect("equal")
line, = ax.plot([], [], '', ms=10)
planet1 = plt.Circle((0,0), r1, facecolor=(0,0,1))
ax.add_artist(planet1)
planet2 = plt.Circle((0,0), r2, facecolor=(1,0,0))
ax.add_artist(planet2)
planet3 = plt.Circle((0,0), r3, facecolor=(1,1,0))
ax.add_artist(planet3)
planet4 = plt.Circle((0,0), r4, facecolor=(0,1,0))
ax.add_artist(planet4)
time_template = 'Time = %.1f s' # prints running simulation time
time_text = ax.text(0.05, 0.9, '', transform=ax.transAxes)
ani = animation.FuncAnimation(fig, simPoints, simData, blit=False,\
interval=10, repeat=True)
plt.show()
最佳答案
假设您实际上只是想调整“轴”限制以“跟随”您的一颗行星，则可以像分配行星一样访问行星的中心-行星和轴都是全局变量。
对simPoints的这些修改使蓝色星球保持在轴心。
def simPoints(simData):
x, t = simData[0], simData[1]
time_text.set_text(time_template%(t))
line.set_data(t, x)
ctr = planet1.center
ax.set_xlim(ctr[0]-430000000, ctr[0]+430000000)
ax.set_ylim(ctr[1]-430000000, ctr[1]+430000000)
return line, time_text