def test_set_force_throws_exception_for_zero_mass(self):
testObj = Particle(self.positionList,
acceleration=np.array(self.acceleration),
mass=0)
force = np.array([5.5, -3, 0.1])
with self.assertRaises(ValueError):
testObj.set_force(force)
def test_update_motion_returns_same_position_for_no_velocity_or_accel(
self):
testObj = Particle(self.positionList)
dtime = 10
testObj.update_motion(dtime)
expected_position = self.positionList
actual_position = testObj.position
np.testing.assert_equal(expected_position, actual_position)
def test_update_motion_returns_expected_position_for_given_velocity(self):
testObj = Particle(self.positionList, self.velocity)
expected_position = np.array(self.positionList)
constant_velocity = np.array(self.velocity)
dtime = 10
testObj.update_motion(10)
expected_position = expected_position + (constant_velocity * dtime)
actual_position = testObj.position
np.testing.assert_equal(expected_position, actual_position)
def test_set_force_stores_expected_force_and_acceleration_value(self):
testObj = Particle(
self.positionList,
acceleration=np.array(self.acceleration),
mass=2.5,
)
force = np.array([5.5, -3, 0.1])
testObj.set_force(force)
expected_force = force
expected_acceleration = force / 2.5
actual_force = testObj.force
actual_acceleration = testObj.acceleration
np.testing.assert_equal(expected_force, actual_force)
np.testing.assert_equal(expected_acceleration, actual_acceleration)
def test_set_force_gives_zero_acceleration_for_infinite_mass(self):
testObj = Particle(
self.positionList,
acceleration=np.array(self.acceleration),
mass=np.inf,
)
force = np.array([5.5, -3, 0.1])
testObj.set_force(force)
expected_force = force
expected_acceleration = np.array([0, 0, 0])
actual_force = testObj.force
actual_acceleration = testObj.acceleration
np.testing.assert_equal(expected_force, actual_force)
np.testing.assert_equal(expected_acceleration, actual_acceleration)
def test_update_motion_returns_expected_position_and_velocity_for_given_accel(
self):
testObj = Particle(self.positionList, self.velocity, self.acceleration)
expected_position = np.array(self.positionList)
initial_velocity = np.array(self.velocity)
acceleration = np.array(self.acceleration)
dtime = 10
testObj.update_motion(10)
expected_position = (expected_position + (initial_velocity * dtime) +
(acceleration * (dtime**2)) / 2)
expected_velocity = initial_velocity + (acceleration * dtime)
actual_position = testObj.position
actual_velocity = testObj.velocity
np.testing.assert_equal(expected_position, actual_position)
np.testing.assert_equal(expected_velocity, actual_velocity)
def test_that_az_decorator_gives_the_correct_acceleration_value(self):
testObj = Particle(self.positionList, acceleration=self.acceleration)
self.assertEqual(testObj.az, self.acceleration[2])
def test_nparray_acceleration_input_matches_nparr_acceleration_attribute_after_init(
self):
testObj = Particle(self.positionList,
acceleration=np.array(self.acceleration))
np.testing.assert_allclose(testObj.acceleration,
np.array(self.acceleration))
def test_acceleration_attribute_not_equal_list_after_init_using_list(self):
testObj = Particle(self.positionList, acceleration=self.acceleration)
assert ~isinstance(testObj.acceleration, list)
def test_nparray_velocity_input_matches_nparr_velocity_attribute_after_init(
self):
testObj = Particle(self.positionList, velocity=np.array(self.velocity))
np.testing.assert_allclose(testObj.velocity, np.array(self.velocity))
def test_velocity_attribute_not_equal_list_after_init_using_list(self):
testObj = Particle(self.positionList, velocity=self.velocity)
assert ~isinstance(testObj.velocity, list)
def test_nparray_pos_input_matches_nparr_pos_attribute_after_init(self):
testObj = Particle(np.array(self.positionList))
np.testing.assert_allclose(testObj.position,
np.array(self.positionList))
def test_pos_attribute_not_equal_list_after_init_using_list(self):
testObj = Particle(self.positionList)
assert ~isinstance(testObj.position, list)
def test_that_3D_numpy_array_returns_an_object_of_type_Particle(self):
assert isinstance(Particle(np.array(self.positionList)), Particle)
def test_that_3D_position_list_returns_an_object_of_type_Particle(self):
assert isinstance(Particle(self.positionList), Particle)
def test_that_vz_decorator_gives_the_correct_velocity_value(self):
testObj = Particle(self.positionList, velocity=self.velocity)
self.assertEqual(testObj.vz, self.velocity[2])
def test_that_z_decorator_gives_the_correct_pos_value(self):
testObj = Particle(self.positionList)
self.assertEqual(testObj.z, self.positionList[2])
def test_energy_kinetic_returns_expected_value(self):
mass = 6.5
velocity = np.array(self.velocity)
testObj = Particle(self.positionList, velocity, mass=mass)
np.testing.assert_equal(testObj.energy_kinetic,
(mass * (velocity**2)) / 2)
def test_momentum_returns_expected_value(self):
mass = 2.5
velocity = np.array(self.velocity)
testObj = Particle(self.positionList, velocity, mass=mass)
np.testing.assert_equal(testObj.momentum, mass * velocity)