def exercise_basic():
assert approx_equal(sum(spatial_lib.xrot((1, 2, 3, 4, 5, 6, 7, 8, 9))), 90)
assert approx_equal(sum(spatial_lib.xtrans((1, 2, 3))), 6)
assert approx_equal(
sum(
spatial_lib.cb_as_spatial_transform(cb=matrix.rt(((1, 2, 3, 4, 5,
6, 7, 8, 9),
(1, 2, 3))))),
90)
assert approx_equal(sum(spatial_lib.crm((1, 2, 3, 4, 5, 6))), 0)
assert approx_equal(sum(spatial_lib.crf((1, 2, 3, 4, 5, 6))), 0)
i_spatial = spatial_lib.mci(m=1.234,
c=matrix.col((1, 2, 3)),
i=matrix.sym(sym_mat3=(2, 3, 4, 0.1, 0.2,
0.3)))
assert approx_equal(sum(i_spatial), 21.306)
assert approx_equal(
spatial_lib.kinetic_energy(i_spatial=i_spatial,
v_spatial=matrix.col((1, 2, 3, 4, 5, 6))),
75.109)
#
mass_points = body_lib.mass_points(sites=matrix.col_list([
(0.949, 2.815, 5.189), (0.405, 3.954, 5.917), (0.779, 5.262, 5.227)
]),
masses=[2.34, 3.56, 1.58])
assert approx_equal(mass_points.sum_of_masses(), 7.48)
assert approx_equal(mass_points.center_of_mass(),
[0.654181818182, 3.87397058824, 5.54350802139])
assert approx_equal(mass_points._sum_of_masses, 7.48)
assert approx_equal(
mass_points.inertia(pivot=matrix.col((0.9, -1.3, 0.4))), [
404.7677928, 10.04129606, 10.09577652, 10.04129606, 199.7384559,
-199.3511949, 10.09577652, -199.3511949, 206.8314171
])
def spatial_inertia(O, alignment_cb_0b=None):
center_of_mass = O.center_of_mass()
inertia = O.inertia(pivot=center_of_mass)
if (alignment_cb_0b is not None):
center_of_mass = alignment_cb_0b * center_of_mass
inertia = alignment_cb_0b.r * inertia * alignment_cb_0b.r.transpose()
return spatial_lib.mci(m=O._sum_of_masses, c=center_of_mass, i=inertia)
def exercise_basic():
assert approx_equal(sum(spatial_lib.xrot((1,2,3,4,5,6,7,8,9))), 90)
assert approx_equal(sum(spatial_lib.xtrans((1,2,3))), 6)
assert approx_equal(
sum(spatial_lib.cb_as_spatial_transform(
cb=matrix.rt(((1,2,3,4,5,6,7,8,9), (1,2,3))))), 90)
assert approx_equal(sum(spatial_lib.crm((1,2,3,4,5,6))), 0)
assert approx_equal(sum(spatial_lib.crf((1,2,3,4,5,6))), 0)
i_spatial = spatial_lib.mci(
m=1.234,
c=matrix.col((1,2,3)),
i=matrix.sym(sym_mat3=(2,3,4,0.1,0.2,0.3)))
assert approx_equal(sum(i_spatial), 21.306)
assert approx_equal(spatial_lib.kinetic_energy(
i_spatial=i_spatial, v_spatial=matrix.col((1,2,3,4,5,6))), 75.109)
#
mass_points = body_lib.mass_points(
sites=matrix.col_list([
(0.949, 2.815, 5.189),
(0.405, 3.954, 5.917),
(0.779, 5.262, 5.227)]),
masses=[2.34, 3.56, 1.58])
assert approx_equal(mass_points.sum_of_masses(), 7.48)
assert approx_equal(mass_points.center_of_mass(),
[0.654181818182, 3.87397058824, 5.54350802139])
assert approx_equal(mass_points._sum_of_masses, 7.48)
assert approx_equal(
mass_points.inertia(pivot=matrix.col((0.9,-1.3,0.4))),
[404.7677928, 10.04129606, 10.09577652,
10.04129606, 199.7384559, -199.3511949,
10.09577652, -199.3511949, 206.8314171])
def spatial_inertia(O, alignment_cb_0b=None):
center_of_mass = O.center_of_mass()
inertia = O.inertia(pivot=center_of_mass)
if (alignment_cb_0b is not None):
center_of_mass = alignment_cb_0b * center_of_mass
inertia = alignment_cb_0b.r * inertia * alignment_cb_0b.r.transpose(
)
return spatial_lib.mci(m=O._sum_of_masses, c=center_of_mass, i=inertia)
