57 lines
2.0 KiB
Python
Executable File
57 lines
2.0 KiB
Python
Executable File
#!/usr/bin/python
|
|
# -*- coding:utf-8 -*-
|
|
from sys import exit as sysexit
|
|
import numpy as np
|
|
import matplotlib.pyplot as plt
|
|
from lib.objects import Body, System
|
|
from lib.plots import display_parameters
|
|
from lib.units import *
|
|
|
|
def main():
|
|
#initialisation
|
|
m = np.array([1., 1., 1e-5])*Ms # Masses in Solar mass
|
|
a = np.array([1., 1., 5.])*au # Semi-major axis in astronomical units
|
|
e = np.array([0., 0., 1./4.]) # Eccentricity
|
|
psi = np.array([0., 0., 0.])*np.pi/180. # Inclination of the orbital plane in degrees
|
|
|
|
x1 = np.array([0., -1., 0.])*a[0]
|
|
x2 = np.array([0., 1., 0.])*a[1]
|
|
x3 = np.array([np.cos(psi[2]), 0., np.sin(psi[2])])*a[2]
|
|
q = np.array([x1, x2, x3])
|
|
|
|
v1 = np.array([np.sqrt(G*m[1]**2/((m[0]+m[1])*np.sqrt(np.sum((q[0]-q[1])**2)))), 0., 0.])
|
|
v2 = np.array([-np.sqrt(G*m[0]**2/((m[0]+m[1])*np.sqrt(np.sum((q[0]-q[1])**2)))), 0., 0.])
|
|
v3 = np.array([0., np.sqrt(G*(m[0]+m[1])*(2./np.sqrt(np.sum(q[2]**2))-1./a[2])), 0.])
|
|
v = np.array([v1, v2, v3])
|
|
|
|
#integration parameters
|
|
duration, step = 100*yr, np.array([1./(365.25*2.), 1./365.25])*yr #integration time and step in years
|
|
integrator = "leapfrog"
|
|
n_bodies = 2
|
|
display = False
|
|
savename = "{0:d}bodies_{1:s}".format(n_bodies, integrator)
|
|
|
|
#simulation start
|
|
bodylist = []
|
|
for i in range(n_bodies):
|
|
bodylist.append(Body(m[i], q[i], v[i]))
|
|
dyn_syst = System(bodylist)
|
|
dyn_syst.COMShift()
|
|
|
|
E, L = [], []
|
|
for step0 in step:
|
|
if integrator.lower() in ['leapfrog', 'frogleap', 'frog']:
|
|
E0, L0 = dyn_syst.leapfrog(duration, step0, recover_param=True, display=display, savename=savename)
|
|
elif integrator.lower() in ['hermite','herm']:
|
|
E0, L0 = dyn_syst.hermite(duration, step0, recover_param=True, display=display, savename=savename)
|
|
E.append(E0)
|
|
L.append(L0)
|
|
|
|
parameters = [duration, step, dyn_syst, integrator]
|
|
display_parameters(E, L, parameters=parameters, savename=savename)
|
|
|
|
return 0
|
|
|
|
if __name__ == '__main__':
|
|
sysexit(main())
|