def reset_system(integrator_num):
body_list = []
body_list.append(body(5, [0, 0], [-1 / 5, 0], [0, 0]))
body_list.append(body(1, [0, 1], [1, 0], [0, 0]))
system = nbody_system(body_list)
xs = []
ys = []
Edat = []
n = len(body_list)
# lists for saving position data
for i in range(n):
xs.append([])
ys.append([])
for iteration in range(500):
integrator = [system.euler, system.verlet,
system.ruth3][integrator_num]
integrator(0.005)
for i in range(n):
xs[i].append(body_list[i].pos[0])
ys[i].append(body_list[i].pos[1])
Edat.append(system.total_energy())
for i in range(n):
plt.plot(xs[i], ys[i])
# plot last points
last_xs = [x[-1] for x in xs]
last_ys = [y[-1] for y in ys]
plt.scatter(last_xs, last_ys)
return xs, ys, Edat
import matplotlib as mpl
import matplotlib.pyplot as plt
from gravitational_system import nbody_system
from body import body
body_list = []
body_list.append(body(5, [0, 0], [-1 / 5, 0], [0, 0]))
body_list.append(body(1, [0, 1], [1, 0], [0, 0]))
system = nbody_system(body_list)
xs = []
ys = []
E_data = []
n = len(body_list)
# lists for saving position data
for i in range(n):
xs.append([])
ys.append([])
for iteration in range(500):
# Choose numerical method; verlet, euler, ruth3
system.ruth3(0.005)
for i in range(n):
xs[i].append(body_list[i].pos[0])
ys[i].append(body_list[i].pos[1])
E_data.append(system.total_energy())
# list containing all celestial bodies
body_list = []
np.set_printoptions(15)
# load initial conditions from file
input_file = csv.DictReader(open("initial.csv", encoding="utf8"))
for b in input_file:
pos = [float(x) for x in [b["x"], b["y"], b["z"]]]
vel = [float(x) for x in [b["vx"], b["vy"], b["vz"]]]
GM = float(b["GM"])
name = b["name"]
body_list.append(body(GM, pos, vel, [0, 0, 0], name))
system = nbody_system(body_list, 1.4881852e-34)
BodyID = 3
years = 10
stepperday = 4
stepsize = 1 / stepperday # days
plot_interval = 1 # log once every x days
offset = 5 # leap days etc
focus_pos = []
earth_data = []