def test_stationary():
# time
t = numpy.asarray([0, 1])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([0, 0])
channels = motion_6d(t, x, y, z)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
-1, abs=1e-2), "did not expect acceleration other than g in z"
def test_with_initial_downward_velocity_but_no_acceleration_more_steps():
# time
t = numpy.asarray([0, 1, 2])
# position
x = numpy.asarray([0, 0, 0])
y = numpy.asarray([0, 0, 0])
z = numpy.asarray([20, 10, 0])
channels = motion_6d(t, x, y, z, vz0=-10.0)
assert channels[0][1:] == pytest.approx(0), "did not expect g in x"
assert channels[1][1:] == pytest.approx(0), "did not expect g in y"
assert channels[2][1:] == pytest.approx(
-1), "did not expect acceleration other than g in z"
def test_freefall_from_stationary():
# time
t = numpy.asarray([0, 4.515])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([100, 0])
channels = motion_6d(t, x, y, z)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
0, abs=1e-2), "expected zero g while freefalling"
def test_stationary_rotate_by_half_pi_around_x():
# time
t = numpy.asarray([0, 1])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([0, 0])
rx = numpy.asarray([0, 0.50]) * numpy.pi
channels = motion_6d(t, x, y, z, rx=rx)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(-1), "expected g to show up in y"
assert channels[2][1] == pytest.approx(0), "did not expect g in z"
def test_accelerate_decelerate():
# time
t = numpy.asarray([0, 2, 4])
# position
x = numpy.asarray([0, 0, 0])
y = numpy.asarray([0, 0, 0])
z = numpy.asarray([0, 9.81, 9.81])
channels = motion_6d(t, x, y, z)
assert channels[0][1:] == pytest.approx(0), "did not expect g in x"
assert channels[1][1:] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
-1.5), "expected half an extra g in z while accelerating"
assert channels[2][2] == pytest.approx(0), "expected zero g in z"
def test_with_initial_downward_velocity_and_gravitational_acceleration_more_steps(
):
# time
t = numpy.asarray([0, 3.6095, 3.6095 + 1.8375])
# position
x = numpy.asarray([0, 0, 0])
y = numpy.asarray([0, 0, 0])
z = numpy.asarray([200, 100, 0])
channels = motion_6d(t, x, y, z, vz0=-10.0)
assert channels[0][1:] == pytest.approx(0), "did not expect g in x"
assert channels[1][1:] == pytest.approx(0), "did not expect g in y"
assert channels[2][1:] == pytest.approx(
0, abs=1e-3), "expected zero g in z while freefalling"
def test_freefall_with_initial_velocity():
# time
t = numpy.asarray([0, 3.6095])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([100, 0])
vz0 = -10.0
channels = motion_6d(t, x, y, z, vz0=vz0)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
0, abs=1e-2), "expected zero g while freefalling"
def test_stationary_rotate_by_half_pi_around_z():
# time
t = numpy.asarray([0, 1])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([0, 0])
rz = numpy.asarray([0, 0.5]) * numpy.pi
channels = motion_6d(t, x, y, z, rz=rz)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
-1), "did not expect acceleration other than g in z"
def test_stationary_rotate_by_one_pi_around_y():
# time
t = numpy.asarray([0, 1])
# position
x = numpy.asarray([0, 0])
y = numpy.asarray([0, 0])
z = numpy.asarray([0, 0])
ry = numpy.asarray([0, 1]) * numpy.pi
channels = motion_6d(t, x, y, z, ry=ry)
assert channels[0][1] == pytest.approx(0), "did not expect g in x"
assert channels[1][1] == pytest.approx(0), "did not expect g in y"
assert channels[2][1] == pytest.approx(
1), "did not expect acceleration other than upside-down g in z"
