def test_bouncing_ball1():

    from siconos.kernel import LagrangianLinearTIDS, NewtonImpactNSL, \
        LagrangianLinearTIR, Interaction, Model, MoreauJeanOSI, TimeDiscretisation, LCP, TimeStepping

    from numpy import array, eye, empty

    t0 = 0       # start time
    T = 10       # end time
    h = 0.005    # time step
    r = 0.1      # ball radius
    g = 9.81     # gravity
    m = 1        # ball mass
    e = 0.9      # restitution coeficient
    theta = 0.5  # theta scheme

    #
    # dynamical system
    #
    x = array([1, 0, 0])  # initial position
    v = array([0, 0, 0])  # initial velocity
    mass = eye(3)         # mass matrix
    mass[2, 2] = 3./5 * r * r

    # the dynamical system
    ball = LagrangianLinearTIDS(x, v, mass)

    # set external forces
    weight = array([-m * g, 0, 0])
    ball.setFExtPtr(weight)

    #
    # Interactions
    #

    # ball-floor
    H = array([[1, 0, 0]])

    nslaw = NewtonImpactNSL(e)
    relation = LagrangianLinearTIR(H)
    inter = Interaction(1, nslaw, relation)

    #
    # Model
    #
    bouncingBall = Model(t0, T)

    # add the dynamical system to the non smooth dynamical system
    bouncingBall.nonSmoothDynamicalSystem().insertDynamicalSystem(ball)

    # link the interaction and the dynamical system
    bouncingBall.nonSmoothDynamicalSystem().link(inter, ball)

    #
    # Simulation
    #

    # (1) OneStepIntegrators
    OSI = MoreauJeanOSI(theta)
    OSI.insertDynamicalSystem(ball)

    # (2) Time discretisation --
    t = TimeDiscretisation(t0, h)

    # (3) one step non smooth problem
    osnspb = LCP()

    # (4) Simulation setup with (1) (2) (3)
    s = TimeStepping(t)
    s.insertIntegrator(OSI)
    s.insertNonSmoothProblem(osnspb)

    # end of model definition

    #
    # computation
    #

    # simulation initialization
    bouncingBall.initialize(s)

    #
    # save and load data from xml and .dat
    #
    try:
        from siconos.io import save
        save(bouncingBall, "bouncingBall.xml")
        save(bouncingBall, "bouncingBall.bin")

    except:
        print("Warning : could not import save from siconos.io")

    # the number of time steps
    N = (T-t0)/h+1

    # Get the values to be plotted
    # ->saved in a matrix dataPlot

    dataPlot = empty((N, 5))

    #
    # numpy pointers on dense Siconos vectors
    #
    q = ball.q()
    v = ball.velocity()
    p = ball.p(1)
    lambda_ = inter.lambda_(1)

    #
    # initial data
    #
    dataPlot[0, 0] = t0
    dataPlot[0, 1] = q[0]
    dataPlot[0, 2] = v[0]
    dataPlot[0, 3] = p[0]
    dataPlot[0, 4] = lambda_[0]

    k = 1

    # time loop
    while(s.hasNextEvent()):
        s.computeOneStep()

        dataPlot[k, 0] = s.nextTime()
        dataPlot[k, 1] = q[0]
        dataPlot[k, 2] = v[0]
        dataPlot[k, 3] = p[0]
        dataPlot[k, 4] = lambda_[0]

        k += 1
        #print(s.nextTime())
        s.nextStep()

    #
    # comparison with the reference file
    #
    from siconos.kernel import SimpleMatrix, getMatrix
    from numpy.linalg import norm

    ref = getMatrix(SimpleMatrix(os.path.join(working_dir, "data/result.ref")))

    assert (norm(dataPlot - ref) < 1e-12)
Exemple #2
0
bouncingBall = Model(t0, T)

# add the dynamical system to the non smooth dynamical system
bouncingBall.nonSmoothDynamicalSystem().insertDynamicalSystem(ball)

# link the interaction and the dynamical system
bouncingBall.nonSmoothDynamicalSystem().link(inter, ball)


#
# Simulation
#

# (1) OneStepIntegrators
OSI = MoreauJeanOSI(theta)
OSI.insertDynamicalSystem(ball)

# (2) Time discretisation --
t = TimeDiscretisation(t0, h)

# (3) one step non smooth problem
osnspb = LCP()

# (4) Simulation setup with (1) (2) (3)
s = TimeStepping(t, OSI, osnspb)


# end of model definition

#
# computation
#
# Model
#
bouncingBox = Model(t0, T)

# add the dynamical system to the non smooth dynamical system
bouncingBox.nonSmoothDynamicalSystem().insertDynamicalSystem(body)

#
# Simulation
#

# (1) OneStepIntegrators
osi = MoreauJeanOSI(theta)
osi.insertDynamicalSystem(body)

ground = btCollisionObject()
ground.setCollisionFlags(btCollisionObject.CF_STATIC_OBJECT)
groundShape = btBoxShape(btVector3(30, 30, .5))
basis = btMatrix3x3()
basis.setIdentity()
ground.getWorldTransform().setBasis(basis)
ground.setCollisionShape(groundShape)
ground.getWorldTransform().getOrigin().setZ(-.5)

# (2) Time discretisation --
timedisc = TimeDiscretisation(t0, h)

# (3) one step non smooth problem
osnspb = FrictionContact(3)