def test_print_properties(self):
"""Ensures the proper printing of segment mass properties. """
# Create parameters.
label = "seg1"
pos = np.array([[1], [2], [3]])
rot = inertia.rotate3([pi / 2, pi / 2, pi / 2])
solids = [self.solidAB, self.solidBC, self.solidCD]
color = (1, 0, 0)
# Create the segment.
seg1 = seg.Segment(label, pos, rot, solids, color)
# For capturing print.
old_stdout = sys.stdout
sys.stdout = mystdout = StringIO()
# Calling print_properties before calc_properties should still work.
seg1.print_properties()
sys.stdout = old_stdout
desStr = (
"seg1 properties:\n\n"
+ "Mass (kg): 4299.15404857 \n\n"
+ "COM in local segment frame (m):\n"
+ "[[ 0. ]\n"
+ " [ 0. ]\n"
+ " [ 11.3248746]] \n\n"
+ "COM in fixed human frame (m):\n"
+ "[[ 12.3248746]\n"
+ " [ 2. ]\n"
+ " [ 3. ]] \n\n"
+ "Inertia tensor in segment frame about local segment "
+ "COM (kg-m^2):\n"
+ "[[ 50287.48961483 0. 0. ]\n"
+ " [ 0. 113733.59619149 0. ]\n"
+ " [ 0. 0. 112963.70547987]] \n\n"
+ "Inertia tensor in fixed human frame about local segment "
+ "COM (kg-m^2):\n"
+ "[[ 1.12963705e+05 1.15452283e-44 2.34998170e-28]\n"
+ " [ 1.15452283e-44 1.13733596e+05 3.88495357e-12]\n"
+ " [ 2.34998170e-28 3.88495357e-12 5.02874896e+04]] \n\n"
)
print "hi"
print mystdout.getvalue()
self.assertEquals(mystdout.getvalue(), desStr)
def test_print_solid_properties(self):
# Create parameters.
label = "seg1"
pos = np.array([[1], [2], [3]])
rot = inertia.rotate3([pi / 2, pi / 2, pi / 2])
solids = [self.solidAB, self.solidBC, self.solidCD]
color = (1, 0, 0)
# Create the segment.
seg1 = seg.Segment(label, pos, rot, solids, color)
old_stdout = sys.stdout
sys.stdout = mystdout = StringIO()
seg1.print_solid_properties()
sys.stdout = old_stdout
desStr = open(os.path.join(os.path.split(__file__)[0], "segment_print_solid_des.txt"), "r").read()
self.assertEquals(mystdout.getvalue(), desStr)
def test_calc_properties(self):
"""Ensures proper calculation of global-frame COM and Inertia."""
# Create parameters.
label = "seg1"
pos = np.array([[1], [2], [3]])
rot = inertia.rotate3([pi / 2, pi / 2, pi / 2])
solids = [self.solidAB, self.solidBC, self.solidCD]
color = (1, 0, 0)
# Create the segment.
seg1 = seg.Segment(label, pos, rot, solids, color)
seg1.calc_properties()
testing.assert_allclose(seg1.COM, np.array([[seg1.relCOM[2, 0] + 1, 2, 3]]).T)
desXInertia = seg1.relInertia[2, 2]
desYInertia = seg1.relInertia[1, 1]
desZInertia = seg1.relInertia[0, 0]
desInertia = np.mat(np.diag(np.array([desXInertia, desYInertia, desZInertia])))
testing.assert_allclose(seg1.Inertia, desInertia, atol=1e-10)
def test_init_bad_input(self):
"""Ensures only proper constructor arguments get through. Exercises
duck-typing.
"""
# Create default parameters.
label = "seg1"
pos = np.array([[1], [2], [3]])
rot = inertia.rotate3([pi / 2, pi / 2, pi / 2])
solids = [self.solidAB, self.solidBC, self.solidCD]
color = (1, 0, 0)
# Empty position.
self.assertRaises(AttributeError, seg.Segment, label, [], rot, solids, color)
# Non-numpy position.
self.assertRaises(AttributeError, seg.Segment, label, [0, 0, 0], rot, solids, color)
# Wrong dimensions.
self.assertRaises(ValueError, seg.Segment, label, pos[1:2, :], rot, solids, color)
# Empty rotation.
self.assertRaises(ValueError, seg.Segment, label, pos, [], solids, color)
# Wrong type rot.
self.assertRaises(ValueError, seg.Segment, label, pos, pos, solids, color)
# Wrong dimensions rot.
self.assertRaises(ValueError, seg.Segment, label, pos, np.mat(pos), solids, color)
# Empty solids.
self.assertRaises(IndexError, seg.Segment, label, pos, rot, [], color)
# Missing color.
self.assertRaises(TypeError, seg.Segment, label, pos, rot, solids)
# Test just having one solid; make sure we do not depend on a segment
# having multiple solids.
# Should not raise exception.
seg1 = seg.Segment(label, pos, rot, [self.solidAB], color)
# Objects in the solids list are not actually `Solid`'s.
self.assertRaises(AttributeError, seg.Segment, label, pos, rot, ["1", "2"], color)
def test_init_real_input(self):
"""Ensures the constructor for valid input makes correct calculations.
"""
# Create parameters.
label = "seg1"
pos = np.array([[1], [2], [3]])
rot = inertia.rotate3([pi / 2, pi / 2, pi / 2])
solids = [self.solidAB, self.solidBC, self.solidCD]
color = (1, 0, 0)
# Create the segment.
seg1 = seg.Segment(label, pos, rot, solids, color)
# Check that parameters were set.
assert seg1.label == label
assert (seg1.pos == pos).all()
assert (seg1.RotMat == rot).all()
assert seg1.solids == solids
assert seg1.nSolids == len(solids)
assert seg1.color == color
# -- Check the other constructor actions.
# Setting orientations of all constituent solids.
assert (seg1.solids[0].pos == pos).all()
assert (seg1.solids[0].RotMat == rot).all()
pos2 = np.array([[6], [2], [3]])
assert (seg1.solids[0].endpos == pos2).all()
# 2nd solid in the segment.
assert (seg1.solids[1].pos == pos2).all()
assert (seg1.solids[1].RotMat == rot).all()
# See definition of solids in setUp().
pos3 = pos2 + np.array([[6], [0], [0]])
assert (seg1.solids[1].endpos == pos3).all()
# 3rd solid in the segment.
assert (seg1.solids[2].pos == pos3).all()
assert (seg1.solids[2].RotMat == rot).all()
# See definition of solids in setUp().
pos4 = pos3 + np.array([[7], [0], [0]])
assert (seg1.solids[2].endpos == pos4).all()
# Other segment-wide attributes we define.
assert (seg1.endpos == pos4).all()
assert (seg1.length == (5 + 6 + 7)).all()
# -- The constructor then calls calc_rel_properties().
desMass = self.solidAB.Mass + self.solidBC.Mass + self.solidCD.Mass
testing.assert_almost_equal(seg1.Mass, desMass)
desRelCOM = (
self.solidAB.Mass * self.solidAB.relCOM
+ self.solidBC.Mass * (self.solidBC.relCOM + np.array([[0, 0, 5]]).T)
+ self.solidCD.Mass * (self.solidCD.relCOM + np.array([[0, 0, 11]]).T)
) / desMass
testing.assert_allclose(seg1.relCOM, desRelCOM)
relCOM_AB = self.solidAB.relCOM
relCOM_BC = np.array([[0, 0, self.solidAB.height]]).T + self.solidBC.relCOM
relCOM_CD = np.array([[0, 0, self.solidAB.height + self.solidBC.height]]).T + self.solidCD.relCOM
desXInertia = (
self.solidAB.relInertia[0, 0]
+ self.solidAB.Mass * (relCOM_AB[2, 0] - seg1.relCOM[2, 0]) ** 2
+ self.solidBC.relInertia[0, 0]
+ self.solidBC.Mass * (relCOM_BC[2, 0] - seg1.relCOM[2, 0]) ** 2
+ self.solidCD.relInertia[0, 0]
+ self.solidCD.Mass * (relCOM_CD[2, 0] - seg1.relCOM[2, 0]) ** 2
)
desYInertia = (
self.solidAB.relInertia[1, 1]
+ self.solidAB.Mass * (relCOM_AB[2, 0] - seg1.relCOM[2, 0]) ** 2
+ self.solidBC.relInertia[1, 1]
+ self.solidBC.Mass * (relCOM_BC[2, 0] - seg1.relCOM[2, 0]) ** 2
+ self.solidCD.relInertia[1, 1]
+ self.solidCD.Mass * (relCOM_CD[2, 0] - seg1.relCOM[2, 0]) ** 2
)
desZInertia = self.solidAB.relInertia[2, 2] + self.solidBC.relInertia[2, 2] + self.solidCD.relInertia[2, 2]
desRelInertia = np.diag(np.array([desXInertia, desYInertia, desZInertia]))
testing.assert_allclose(seg1.relInertia, desRelInertia)
