class SolarSystem:
def __init__(self, radius, name, time_step, n_bodies):
self._radius = radius
self._name = name
self._body_list = []
self._f_matrix = np.zeros(shape=(3, n_bodies))
self.a_matrix = np.zeros(shape=(3, n_bodies))
self.dt = time_step
self._n_bodies = n_bodies
self._analytics = Analytics()
self._acceleration_analytics = Analytics()
self._velocity_analytics = Analytics()
self._t = 0
def add_body(self, body):
if len(self._body_list) > self._n_bodies:
print(
f"Cannot exceed no. bodies specified in instantiation of solar system ({self._n_bodies})"
)
return
self._body_list.append(body)
def net_forces(self):
""" produces a matrix of force components for all bodies """
self._f_matrix.fill(0)
count = 0
for body in self._body_list:
for body2 in self._body_list:
if body != body2:
net_force = Physics.gravitational_force(
body.get_mass(), body2.get_mass(),
self.euclidean_distance(body.get_position(),
body2.get_position()),
self.get_dist_change(body.get_position(),
body2.get_position()))
self._f_matrix[:, count] += net_force
count += 1
self._analytics.add_data(self._t, la.norm(self._f_matrix[:, 1]))
def acceleration(self):
""" updates acceleration matrix - ax, ay, az for each body """
self.a_matrix.fill(0)
for i, body in enumerate(self._body_list):
self.a_matrix[:, i] = self._f_matrix[:, i] / body.get_mass()
self._acceleration_analytics.add_data(self._t,
la.norm(self.a_matrix[:, 1]))
def velocity(self):
""" updates velocity """
for i, body in enumerate(self._body_list):
v = Physics.velocity(body.get_velocity(), self.dt,
self.a_matrix[:, i])
body.set_position(v, self.dt)
if i == 1:
self._velocity_analytics.add_data(self._t, la.norm(v))
self._t += self.dt
self.render()
@staticmethod
def get_dist_change(pos1, pos2):
""" returns difference in position: x = [dx, dy, dz] """
return pos1 - pos2
@staticmethod
def euclidean_distance(pos1, pos2):
""" calculates Euclidean distance between two particles """
return la.norm(pos1 - pos2)
def render(self):
""" draws new position of all particles """
for body in self._body_list:
body.draw_update()
def plot(self):
self._acceleration_analytics.draw("Acceleration of a planet by time",
"Acceleration (ms^-2)")
self._analytics.draw("Force exerted on a planet by time", "Force (N)")
self._velocity_analytics.draw("Velocity of a planet by time",
"Velocity (ms^-1)")
