def test_apply_gravity():
ganymede = Moon(Position3(3, 5, 6), Position3(0, 1, 2))
calysto = Moon(Position3(5, 3, 6), Position3(3, 4, 5))
ganymede.apply_gravity(calysto)
# Position unchanged
assert ganymede.position == Position3(3, 5, 6)
assert calysto.position == Position3(5, 3, 6)
# velocity changed
assert ganymede.velocity == Position3(0 + 1, 1 - 1, 2 + 0)
assert calysto.velocity == Position3(3 - 1, 4 + 1, 5 + 0)
def test_apply_velocity():
ganymede = Moon(Position3(3, 5, 6), Position3(-1, 2, 2))
calysto = Moon(Position3(5, 3, 6), Position3(4, 3, 5))
ganymede.apply_velocity()
calysto.apply_velocity()
# position changed
assert ganymede.position == Position3(2, 7, 8)
assert calysto.position == Position3(9, 6, 11)
# velocity unchanged
assert ganymede.velocity == Position3(-1, 2, 2)
assert calysto.velocity == Position3(4, 3, 5)
def test_example_1_loading():
system = System(Moon.from_file('example_1.txt'))
exp_moons = [
((-1, 0, 2), (0, 0, 0)),
((2, -10, -7), (0, 0, 0)),
((4, -8, 8), (0, 0, 0)),
((3, 5, -1), (0, 0, 0)),
]
for i, moon in enumerate(system.moons):
assert moon.position == Position3(*exp_moons[i][0])
assert moon.velocity == Position3(*exp_moons[i][1])
def test_example_1_brute_converges():
system = System(Moon.from_file('example_1.txt'))
print(f'Initial state: {system.state()}')
past_states = set()
assert system.brute_convergence(past_states, 1000) is None # 1000
assert system.brute_convergence(past_states, 1770) is None # 2770
assert system.state() == 'M((2,-1,1),(-3,2,2));' \
'M((3,-7,-4),(2,-5,-6));' \
'M((1,-7,5),(0,-3,6));' \
'M((2,2,0),(1,6,-2))'
assert system.brute_convergence(past_states, 1000) == 2
def test_example_1_run_10():
system = System(Moon.from_file('example_1.txt'))
system.run(10)
exp_moons = [
((2, 1, -3), (-3, -2, 1), 36),
((1, -8, 0), (-1, 1, 3), 45),
((3, -6, 1), (3, 2, -3), 80),
((2, 0, 4), (1, -1, -1), 18),
]
for i, moon in enumerate(system.moons):
assert moon.position == Position3(*exp_moons[i][0]), f'For moon {i}'
assert moon.velocity == Position3(*exp_moons[i][1]), f'For moon {i}'
assert moon.total_energy == exp_moons[i][2], f'For moon {i}'
assert system.total_energy == 179
def test_example_1_run_1():
system = System(Moon.from_file('example_1.txt'))
system.print()
system.run(1)
exp_moons = [
((2, -1, 1), (3, -1, -1)),
((3, -7, -4), (1, 3, 3)),
((1, -7, 5), (-3, 1, -3)),
((2, 2, 0), (-1, -3, 1)),
]
for i, moon in enumerate(system.moons):
assert moon.position == Position3(*exp_moons[i][0])
assert moon.velocity == Position3(*exp_moons[i][1])
def test_example_2_run_100():
system = System(Moon.from_file('example_2.txt'))
system.run(100)
exp_moons = [
((8, -12, -9), (-7, 3, 0), 29, 10, 290),
((13, 16, -3), (3, -11, -5), 32, 19, 608),
((-29, -11, -1), (-3, 7, 4), 41, 14, 574),
((16, -13, 23), (7, 1, 1), 52, 9, 468),
]
for i, moon in enumerate(system.moons):
assert moon.position == Position3(*exp_moons[i][0]), f'For moon {i}'
assert moon.velocity == Position3(*exp_moons[i][1]), f'For moon {i}'
assert moon.potential_energy == exp_moons[i][2], f'For moon {i}'
assert moon.kinetic_energy == exp_moons[i][3], f'For moon {i}'
assert moon.total_energy == exp_moons[i][4], f'For moon {i}'
assert system.total_energy == 1940
def test_question_1():
system = System(Moon.from_file('input.txt'))
system.run(1000)
assert system.total_energy == 5517
def test_energy(position, velocity, exp_pot, exp_kin, exp_total):
moon = Moon(position, velocity)
assert moon.potential_energy == exp_pot
assert moon.kinetic_energy == exp_kin
assert moon.total_energy == exp_total