def test_partial_velocity():
q1, q2, q3, u1, u2, u3 = dynamicsymbols('q1 q2 q3 u1 u2 u3')
u4, u5 = dynamicsymbols('u4, u5')
r = symbols('r')
N = ReferenceFrame('N')
Y = N.orientnew('Y', 'Axis', [q1, N.z])
L = Y.orientnew('L', 'Axis', [q2, Y.x])
R = L.orientnew('R', 'Axis', [q3, L.y])
R.set_ang_vel(N, u1 * L.x + u2 * L.y + u3 * L.z)
C = Point('C')
C.set_vel(N, u4 * L.x + u5 * (Y.z ^ L.x))
Dmc = C.locatenew('Dmc', r * L.z)
Dmc.v2pt_theory(C, N, R)
vel_list = [Dmc.vel(N), C.vel(N), R.ang_vel_in(N)]
u_list = [u1, u2, u3, u4, u5]
assert (partial_velocity(vel_list, u_list, N) ==
[[- r*L.y, r*L.x, 0, L.x, cos(q2)*L.y - sin(q2)*L.z],
[0, 0, 0, L.x, cos(q2)*L.y - sin(q2)*L.z],
[L.x, L.y, L.z, 0, 0]])
# Make sure that partial velocities can be computed regardless if the
# orientation between frames is defined or not.
A = ReferenceFrame('A')
B = ReferenceFrame('B')
v = u4 * A.x + u5 * B.y
assert partial_velocity((v, ), (u4, u5), A) == [[A.x, B.y]]
raises(TypeError, lambda: partial_velocity(Dmc.vel(N), u_list, N))
raises(TypeError, lambda: partial_velocity(vel_list, u1, N))
def test_partial_velocity():
q1, q2, q3, u1, u2, u3 = dynamicsymbols('q1 q2 q3 u1 u2 u3')
u4, u5 = dynamicsymbols('u4, u5')
r = symbols('r')
N = ReferenceFrame('N')
Y = N.orientnew('Y', 'Axis', [q1, N.z])
L = Y.orientnew('L', 'Axis', [q2, Y.x])
R = L.orientnew('R', 'Axis', [q3, L.y])
R.set_ang_vel(N, u1 * L.x + u2 * L.y + u3 * L.z)
C = Point('C')
C.set_vel(N, u4 * L.x + u5 * (Y.z ^ L.x))
Dmc = C.locatenew('Dmc', r * L.z)
Dmc.v2pt_theory(C, N, R)
vel_list = [Dmc.vel(N), C.vel(N), R.ang_vel_in(N)]
u_list = [u1, u2, u3, u4, u5]
assert (partial_velocity(vel_list, u_list, N) == [[
-r * L.y, r * L.x, 0, L.x,
cos(q2) * L.y - sin(q2) * L.z
], [0, 0, 0, L.x, cos(q2) * L.y - sin(q2) * L.z], [L.x, L.y, L.z, 0, 0]])
# Make sure that partial velocities can be computed regardless if the
# orientation between frames is defined or not.
A = ReferenceFrame('A')
B = ReferenceFrame('B')
v = u4 * A.x + u5 * B.y
assert partial_velocity((v, ), (u4, u5), A) == [[A.x, B.y]]
raises(TypeError, lambda: partial_velocity(Dmc.vel(N), u_list, N))
raises(TypeError, lambda: partial_velocity(vel_list, u1, N))
def test_partial_velocity():
q1, q2, q3, u1, u2, u3 = dynamicsymbols("q1 q2 q3 u1 u2 u3")
u4, u5 = dynamicsymbols("u4, u5")
r = symbols("r")
N = ReferenceFrame("N")
Y = N.orientnew("Y", "Axis", [q1, N.z])
L = Y.orientnew("L", "Axis", [q2, Y.x])
R = L.orientnew("R", "Axis", [q3, L.y])
R.set_ang_vel(N, u1 * L.x + u2 * L.y + u3 * L.z)
C = Point("C")
C.set_vel(N, u4 * L.x + u5 * (Y.z ^ L.x))
Dmc = C.locatenew("Dmc", r * L.z)
Dmc.v2pt_theory(C, N, R)
vel_list = [Dmc.vel(N), C.vel(N), R.ang_vel_in(N)]
u_list = [u1, u2, u3, u4, u5]
assert partial_velocity(vel_list, u_list, N) == [
[-r * L.y, r * L.x, 0, L.x,
cos(q2) * L.y - sin(q2) * L.z],
[0, 0, 0, L.x, cos(q2) * L.y - sin(q2) * L.z],
[L.x, L.y, L.z, 0, 0],
]
# Make sure that partial velocities can be computed regardless if the
# orientation between frames is defined or not.
A = ReferenceFrame("A")
B = ReferenceFrame("B")
v = u4 * A.x + u5 * B.y
assert partial_velocity((v, ), (u4, u5), A) == [[A.x, B.y]]
raises(TypeError, lambda: partial_velocity(Dmc.vel(N), u_list, N))
raises(TypeError, lambda: partial_velocity(vel_list, u1, N))