def test_simple_prescribed_integration(self):
s = System()
h = Hinge('hinge', [0, 1, 0])
s.add_leaf(h)
s.setup()
s.prescribe(h)
w = h.vstrain[0] = 0.97 # rad/s
integ = Integrator(s)
t, y = integ.integrate(9.0, 0.1)
# Check time vector and shape of result
assert_array_equal(t, np.arange(0, 9.0, 0.1))
self.assertEqual(len(y), 1)
self.assertEqual(y[0].shape, (len(t), 1))
# Result should be y = wt, but wrapped to [0, 2pi)
assert_aae(y[0][:, 0], (w * t) % (2 * np.pi))
# Check asking for velocity and acceleration works
h.xstrain[0] = s.time = 0.0 # reset
integ = Integrator(s, ('pos', 'vel', 'acc'))
t, y = integ.integrate(1.0, 0.1)
assert_array_equal(t, np.arange(0, 1.0, 0.1))
self.assertEqual(len(y), 3)
for yy in y:
self.assertEqual(yy.shape, (len(t), 1))
assert_aae(y[0][:, 0], w * t)
assert_aae(y[1][:, 0], w)
assert_aae(y[2][:, 0], 0)
def simulate(self, xpivot=0.0, vpivot=0.0, t1=10, dt=0.05):
# reset
self.system.q[:] = 0.0
self.system.qd[:] = 0.0
# initial conditions
self.system.q[self.pivot.istrain][0] = xpivot # initial elevation
#self.system.qd[self.pivot.istrain][0] = vpivot # initial elevation spd
self.system.qd[self.axis.istrain][0] = self.spin # constant spin speed
# simulate
integ = Integrator(self.system, ('pos', 'vel'))
integ.integrate(t1, dt, nprint=None)
return integ
def simulate(self, xpivot=0.0, vpivot=0.0, t1=10, dt=0.05):
# reset
self.system.q[:] = 0.0
self.system.qd[:] = 0.0
# initial conditions
self.system.q[self.pivot.istrain][0] = xpivot # initial elevation
#self.system.qd[self.pivot.istrain][0] = vpivot # initial elevation spd
self.system.qd[self.axis.istrain][0] = self.spin # constant spin speed
# simulate
integ = Integrator(self.system, ('pos', 'vel'))
integ.integrate(t1, dt, nprint=None)
return integ
def simulate(system):
# Set initial conditions
system.q[system.elements['hinge'].istrain][0] = 0.3
# Integrate
integ = Integrator(system, ('pos','vel','acc'))
t, y = integ.integrate(5, 0.01, nprint=None)
return integ
def simulate(system):
# Set initial conditions
system.q[system.elements['hinge'].istrain][0] = 0.3
# Integrate
integ = Integrator(system, ('pos', 'vel', 'acc'))
t, y = integ.integrate(5, 0.01, nprint=None)
return integ
def test_callback(self):
s = System()
s.setup()
# Exponential decay: qd = -A q
def callback(system, ti, q_struct, q_other):
self.assertIs(system, s)
self.assertEqual(len(q_other), 1)
return -q_other
integ = Integrator(s)
t, y = integ.integrate(9.0, 0.1, extra_states=np.ones(1),
callback=callback)
# Check time vector and shape of result
assert_array_equal(t, np.arange(0, 9.0, 0.1))
self.assertEqual(len(y), 1)
self.assertEqual(y[0].shape, (len(t), 1))
assert_aae(y[0][:, 0], np.exp(-t))
def integrate(system, callback=None):
integ = Integrator(system)
t, y = integ.integrate(10, 0.5, nprint=None, callback=callback)
return y[0]
def integrate(system, callback=None):
# dopri5 gives exact result for step response
integ = Integrator(system, method='dopri5')
t, y = integ.integrate(10, 0.5, nprint=None, callback=callback)
return t, y[0]
def integrate(system, callback=None):
integ = Integrator(system)
t, y = integ.integrate(10, 0.5, nprint=None, callback=callback)
return y[0]
def integrate(system, callback=None):
# dopri5 gives exact result for step response
integ = Integrator(system, method='dopri5')
t, y = integ.integrate(10, 0.5, nprint=None, callback=callback)
return t, y[0]
