def Initialize(N, Pickle='None', L=3, Center=0, Sun=False):
'''
This function creates the bodies.
In Args:
- N: Number of Bodies to be simulated.
- Pickle: (Optional) Recieves a pickle path to initialize the simulation from it.
- L: "Size" of the initial distribution on the position of the bodies. Default is 3 AU.
- Center: Center of the initial distribution of the bodies positions. Default is 0.
- Sun: (Optional) If 'True' adds a Sun-Like object at the center of the distribution. Default is False.
Out Args:
- Bodies: Array containing the bodies to be simulated.
** Note that if initialized using a pickle, the number of bodies initialized will be the same as the
bodies in the pickle **
'''
if Pickle == 'None':
Bodies = np.zeros(
(N, ),
dtype=object) #Define an array that will contain the Bodies.
r = 2 * L
# Here we iterate to create each particle with a specific velocity and position.
for i in range(N):
# We choose this sigma considering that 3 sigma will represent the 99% of our distribution,
# then, when the majority of the particles wil be within the "scale" of the system.
x = np.random.normal(Center, r / 3.)
y = np.random.normal(Center, r / 3.)
z = np.random.normal(
Center,
0.01) # This is to give the distribution a Disk-like form.
pos = np.array([x, y, z])
mass = np.random.uniform(0.001, 1.)
vx = np.random.uniform(-3, 3)
vy = np.random.uniform(-3, 3)
vz = np.random.uniform(
-0.2, 0.2) #This is to give the distribution a Disk-like form.
vel = np.array([vx, vy, vz])
Bodies[i] = Body(pos, vel, mass,
name='Particle_{}'.format(i)) #Create each body.
if Sun == True: #Add a Main body in our system at the center. (Like a Sun)
if i == N - 1:
pos = np.array([Center, Center, Center])
mass = 5
vel = np.array([0, 0, 0])
Bodies[i] = Body(pos, vel, mass, name='Sun')
#Here we compute the initial acceleration for the bodies.
for i in range(N):
Bodies[i].acceleration_i_1 = Bodies[i].Compute_acceleration(Bodies)
Bodies[i].acceleration_i = Bodies[i].acceleration_i_1
print('System initialized with %d bodies' % (N))
return Bodies
else: # If we initialize from a pickle file.
Imported_Pickle = pickle.load(open(Pickle, 'rb'))
Bodies = Imported_Pickle
print('System initialized with %d bodies from a Pickle file.' %
(len(Bodies)))
return Bodies
