import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as anim
from matplotlib.widgets import Slider, Button, RadioButtons

a=np.loadtxt("kepler.dat")

fig,p=plt.subplots(figsize=(10,10))
p = plt.subplot()
#p=plt.axes(xlim=(-50000, 10000), ylim=(-30000, 30000))
p.set_xlim(-50000, 10000)
p.set_ylim(-30000, 30000)
p.grid()
p.set_aspect("equal")
sat, = p.plot([], [], 'o',color="red")

def animf(i):
    sx = [a[i,1]]
    sy = [a[i,2]]
    sat.set_data(sx, sy)
    return sat,

maa=plt.Circle((0,0),6378,color="green")
p.plot(a[:,1],a[:,2])
p.add_artist(maa)
ani = anim.FuncAnimation(fig, animf, range(0,len(a[:,0]),100),interval=10,repeat=False,blit=True)
plt.show()