예제 #1
0
def test_kv_with_no_charge():
    from random import seed
    seed(0)

    from pyrticle.units import SIUnitsWithNaturalConstants
    units = SIUnitsWithNaturalConstants()

    # discretization setup ----------------------------------------------------
    from hedge.mesh import make_cylinder_mesh
    from hedge.backends import guess_run_context

    rcon = guess_run_context([])

    tube_length = 100 * units.MM
    mesh = make_cylinder_mesh(radius=25 * units.MM,
                              height=tube_length,
                              periodic=True)

    discr = rcon.make_discretization(mesh, order=3)

    dt = discr.dt_factor(units.VACUUM_LIGHT_SPEED()) / 2
    final_time = 1 * units.M / units.VACUUM_LIGHT_SPEED()
    nsteps = int(final_time / dt) + 1
    dt = final_time / nsteps

    # particles setup ---------------------------------------------------------
    from pyrticle.cloud import PicMethod
    from pyrticle.deposition.shape import ShapeFunctionDepositor
    from pyrticle.pusher import MonomialParticlePusher

    method = PicMethod(discr, units, ShapeFunctionDepositor(),
                       MonomialParticlePusher(), 3, 3)

    nparticles = 10000
    cloud_charge = 1e-9 * units.C
    electrons_per_particle = cloud_charge / nparticles / units.EL_CHARGE

    el_energy = 5.2e6 * units.EV
    gamma = el_energy / units.EL_REST_ENERGY()
    beta = (1 - 1 / gamma**2)**0.5

    from pyrticle.distribution import KVZIntervalBeam
    beam = KVZIntervalBeam(units,
                           total_charge=0,
                           p_charge=0,
                           p_mass=electrons_per_particle * units.EL_MASS,
                           radii=2 * [2.5 * units.MM],
                           emittances=2 * [5 * units.MM * units.MRAD],
                           z_length=5 * units.MM,
                           z_pos=10 * units.MM,
                           beta=beta)

    state = method.make_state()
    method.add_particles(state, beam.generate_particles(), nparticles)

    # diagnostics setup -------------------------------------------------------
    from pytools.log import LogManager
    from pyrticle.log import add_beam_quantities, StateObserver
    observer = StateObserver(method, None)
    logmgr = LogManager(mode="w")
    add_beam_quantities(logmgr, observer, axis=0, beam_axis=2)

    from pyrticle.distribution import KVPredictedRadius
    logmgr.add_quantity(
        KVPredictedRadius(dt,
                          beam_v=beta * units.VACUUM_LIGHT_SPEED(),
                          predictor=beam.get_rms_predictor(axis=0),
                          suffix="x_rms"))
    logmgr.add_quantity(
        KVPredictedRadius(dt,
                          beam_v=beta * units.VACUUM_LIGHT_SPEED(),
                          predictor=beam.get_total_predictor(axis=0),
                          suffix="x_total"))

    # timestep loop -----------------------------------------------------------
    vel = method.velocities(state)
    from hedge.tools import join_fields

    def rhs(t, y):
        return join_fields([
            vel,
            0 * vel,
            0,  # drecon
        ])

    from hedge.timestep.runge_kutta import LSRK4TimeStepper
    stepper = LSRK4TimeStepper()
    t = 0

    from pyrticle.cloud import TimesteppablePicState
    ts_state = TimesteppablePicState(method, state)

    for step in xrange(nsteps):
        observer.set_fields_and_state(None, ts_state.state)

        logmgr.tick()

        ts_state = stepper(ts_state, t, dt, rhs)
        method.upkeep(ts_state.state)

        t += dt

    logmgr.tick()

    _, _, err_table = logmgr.get_expr_dataset(
        "(rx_rms-rx_rms_theory)/rx_rms_theory")
    rel_max_rms_error = max(err for step, err in err_table)
    assert rel_max_rms_error < 0.01
예제 #2
0
def main(write_output=True):
    from hedge.timestep import RK4TimeStepper
    from hedge.mesh import make_disk_mesh
    from math import sqrt, pi, exp

    from hedge.backends import guess_run_context, FEAT_CUDA
    rcon = guess_run_context()

    epsilon0 = 8.8541878176e-12 # C**2 / (N m**2)
    mu0 = 4*pi*1e-7 # N/A**2.
    epsilon = 1*epsilon0
    mu = 1*mu0

    c = 1/sqrt(mu*epsilon)

    cylindrical = False
    periodic = False

    pml_width = 0.5
    #mesh = make_mesh(a=numpy.array((-1,-1,-1)), b=numpy.array((1,1,1)), 
    #mesh = make_mesh(a=numpy.array((-3,-3)), b=numpy.array((3,3)), 
    mesh = make_mesh(a=numpy.array((-1,-1)), b=numpy.array((1,1)), 
    #mesh = make_mesh(a=numpy.array((-2,-2)), b=numpy.array((2,2)), 
            pml_width=pml_width, max_volume=0.01)

    if rcon.is_head_rank:
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    class Current:
        def volume_interpolant(self, t, discr):
            from hedge.tools import make_obj_array

            result = discr.volume_zeros(kind="numpy", dtype=numpy.float64)

            omega = 6*c
            if omega*t > 2*pi:
                return make_obj_array([result, result, result])

            x = make_obj_array(discr.nodes.T)
            r = numpy.sqrt(numpy.dot(x, x))

            idx = r<0.3
            result[idx] = (1+numpy.cos(pi*r/0.3))[idx] \
                    *numpy.sin(omega*t)**3

            result = discr.convert_volume(result, kind=discr.compute_kind,
                    dtype=discr.default_scalar_type)
            return make_obj_array([-result, result, result])

    order = 3
    discr = rcon.make_discretization(mesh_data, order=order,
            debug=["cuda_no_plan"])

    from hedge.visualization import VtkVisualizer
    if write_output:
        vis = VtkVisualizer(discr, rcon, "em-%d" % order)

    from hedge.mesh import TAG_ALL, TAG_NONE
    from hedge.data import GivenFunction, TimeHarmonicGivenFunction, TimeIntervalGivenFunction
    from hedge.models.em import MaxwellOperator
    from hedge.models.pml import \
            AbarbanelGottliebPMLMaxwellOperator, \
            AbarbanelGottliebPMLTMMaxwellOperator, \
            AbarbanelGottliebPMLTEMaxwellOperator

    op = AbarbanelGottliebPMLTEMaxwellOperator(epsilon, mu, flux_type=1,
            current=Current(),
            pec_tag=TAG_ALL,
            absorb_tag=TAG_NONE,
            add_decay=True
            )

    fields = op.assemble_ehpq(discr=discr)

    stepper = RK4TimeStepper()

    if rcon.is_head_rank:
        print "order %d" % order
        print "#elements=", len(mesh.elements)

    # diagnostics setup ---------------------------------------------------
    from pytools.log import LogManager, add_general_quantities, \
            add_simulation_quantities, add_run_info

    if write_output:
        log_file_name = "maxwell-%d.dat" % order
    else:
        log_file_name = None

    logmgr = LogManager(log_file_name, "w", rcon.communicator)
    add_run_info(logmgr)
    add_general_quantities(logmgr)
    add_simulation_quantities(logmgr)
    discr.add_instrumentation(logmgr)
    stepper.add_instrumentation(logmgr)

    from pytools.log import IntervalTimer
    vis_timer = IntervalTimer("t_vis", "Time spent visualizing")
    logmgr.add_quantity(vis_timer)

    from hedge.log import EMFieldGetter, add_em_quantities
    field_getter = EMFieldGetter(discr, op, lambda: fields)
    add_em_quantities(logmgr, op, field_getter)

    logmgr.add_watches(["step.max", "t_sim.max", ("W_field", "W_el+W_mag"), "t_step.max"])

    from hedge.log import LpNorm
    class FieldIdxGetter:
        def __init__(self, whole_getter, idx):
            self.whole_getter = whole_getter
            self.idx = idx

        def __call__(self):
            return self.whole_getter()[self.idx]

    # timestep loop -------------------------------------------------------

    t = 0
    pml_coeff = op.coefficients_from_width(discr, width=pml_width)
    rhs = op.bind(discr, pml_coeff)

    try:
        from hedge.timestep import times_and_steps
        step_it = times_and_steps(
                final_time=4/c, logmgr=logmgr,
                max_dt_getter=lambda t: op.estimate_timestep(discr,
                    stepper=stepper, t=t, fields=fields))

        for step, t, dt in step_it:
            if step % 10 == 0 and write_output:
                e, h, p, q = op.split_ehpq(fields)
                visf = vis.make_file("em-%d-%04d" % (order, step))
                #pml_rhs_e, pml_rhs_h, pml_rhs_p, pml_rhs_q = \
                        #op.split_ehpq(rhs(t, fields))
                j = Current().volume_interpolant(t, discr)
                vis.add_data(visf, [ 
                    ("e", discr.convert_volume(e, "numpy")), 
                    ("h", discr.convert_volume(h, "numpy")), 
                    ("p", discr.convert_volume(p, "numpy")), 
                    ("q", discr.convert_volume(q, "numpy")), 
                    ("j", discr.convert_volume(j, "numpy")), 
                    #("pml_rhs_e", pml_rhs_e),
                    #("pml_rhs_h", pml_rhs_h),
                    #("pml_rhs_p", pml_rhs_p),
                    #("pml_rhs_q", pml_rhs_q),
                    #("max_rhs_e", max_rhs_e),
                    #("max_rhs_h", max_rhs_h),
                    #("max_rhs_p", max_rhs_p),
                    #("max_rhs_q", max_rhs_q),
                    ], 
                    time=t, step=step)
                visf.close()

            fields = stepper(fields, t, dt, rhs)

        _, _, energies_data = logmgr.get_expr_dataset("W_el+W_mag")
        energies = [value for tick_nbr, value in energies_data]

        assert energies[-1] < max(energies) * 1e-2

    finally:
        logmgr.close()

        if write_output:
            vis.close()
예제 #3
0
def main(write_output=True):
    from hedge.timestep.runge_kutta import LSRK4TimeStepper
    from math import sqrt, pi, exp

    from hedge.backends import guess_run_context
    rcon = guess_run_context()

    epsilon0 = 8.8541878176e-12  # C**2 / (N m**2)
    mu0 = 4 * pi * 1e-7  # N/A**2.
    epsilon = 1 * epsilon0
    mu = 1 * mu0

    c = 1 / sqrt(mu * epsilon)

    pml_width = 0.5
    #mesh = make_mesh(a=np.array((-1,-1,-1)), b=np.array((1,1,1)),
    #mesh = make_mesh(a=np.array((-3,-3)), b=np.array((3,3)),
    mesh = make_mesh(
        a=np.array((-1, -1)),
        b=np.array((1, 1)),
        #mesh = make_mesh(a=np.array((-2,-2)), b=np.array((2,2)),
        pml_width=pml_width,
        max_volume=0.01)

    if rcon.is_head_rank:
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    class Current:
        def volume_interpolant(self, t, discr):
            from hedge.tools import make_obj_array

            result = discr.volume_zeros(kind="numpy", dtype=np.float64)

            omega = 6 * c
            if omega * t > 2 * pi:
                return make_obj_array([result, result, result])

            x = make_obj_array(discr.nodes.T)
            r = np.sqrt(np.dot(x, x))

            idx = r < 0.3
            result[idx] = (1+np.cos(pi*r/0.3))[idx] \
                    *np.sin(omega*t)**3

            result = discr.convert_volume(result,
                                          kind=discr.compute_kind,
                                          dtype=discr.default_scalar_type)
            return make_obj_array([-result, result, result])

    order = 3
    discr = rcon.make_discretization(mesh_data,
                                     order=order,
                                     debug=["cuda_no_plan"])

    from hedge.visualization import VtkVisualizer
    if write_output:
        vis = VtkVisualizer(discr, rcon, "em-%d" % order)

    from hedge.mesh import TAG_ALL, TAG_NONE
    from hedge.data import GivenFunction, TimeHarmonicGivenFunction, TimeIntervalGivenFunction
    from hedge.models.em import MaxwellOperator
    from hedge.models.pml import \
            AbarbanelGottliebPMLMaxwellOperator, \
            AbarbanelGottliebPMLTMMaxwellOperator, \
            AbarbanelGottliebPMLTEMaxwellOperator

    op = AbarbanelGottliebPMLTEMaxwellOperator(epsilon,
                                               mu,
                                               flux_type=1,
                                               current=Current(),
                                               pec_tag=TAG_ALL,
                                               absorb_tag=TAG_NONE,
                                               add_decay=True)

    fields = op.assemble_ehpq(discr=discr)

    stepper = LSRK4TimeStepper()

    if rcon.is_head_rank:
        print "order %d" % order
        print "#elements=", len(mesh.elements)

    # diagnostics setup ---------------------------------------------------
    from pytools.log import LogManager, add_general_quantities, \
            add_simulation_quantities, add_run_info

    if write_output:
        log_file_name = "maxwell-%d.dat" % order
    else:
        log_file_name = None

    logmgr = LogManager(log_file_name, "w", rcon.communicator)
    add_run_info(logmgr)
    add_general_quantities(logmgr)
    add_simulation_quantities(logmgr)
    discr.add_instrumentation(logmgr)
    stepper.add_instrumentation(logmgr)

    from pytools.log import IntervalTimer
    vis_timer = IntervalTimer("t_vis", "Time spent visualizing")
    logmgr.add_quantity(vis_timer)

    from hedge.log import EMFieldGetter, add_em_quantities
    field_getter = EMFieldGetter(discr, op, lambda: fields)
    add_em_quantities(logmgr, op, field_getter)

    logmgr.add_watches(
        ["step.max", "t_sim.max", ("W_field", "W_el+W_mag"), "t_step.max"])

    from hedge.log import LpNorm

    class FieldIdxGetter:
        def __init__(self, whole_getter, idx):
            self.whole_getter = whole_getter
            self.idx = idx

        def __call__(self):
            return self.whole_getter()[self.idx]

    # timestep loop -------------------------------------------------------

    t = 0
    pml_coeff = op.coefficients_from_width(discr, width=pml_width)
    rhs = op.bind(discr, pml_coeff)

    try:
        from hedge.timestep import times_and_steps
        step_it = times_and_steps(
            final_time=4 / c,
            logmgr=logmgr,
            max_dt_getter=lambda t: op.estimate_timestep(
                discr, stepper=stepper, t=t, fields=fields))

        for step, t, dt in step_it:
            if step % 10 == 0 and write_output:
                e, h, p, q = op.split_ehpq(fields)
                visf = vis.make_file("em-%d-%04d" % (order, step))
                #pml_rhs_e, pml_rhs_h, pml_rhs_p, pml_rhs_q = \
                #op.split_ehpq(rhs(t, fields))
                j = Current().volume_interpolant(t, discr)
                vis.add_data(
                    visf,
                    [
                        ("e", discr.convert_volume(e, "numpy")),
                        ("h", discr.convert_volume(h, "numpy")),
                        ("p", discr.convert_volume(p, "numpy")),
                        ("q", discr.convert_volume(q, "numpy")),
                        ("j", discr.convert_volume(j, "numpy")),
                        #("pml_rhs_e", pml_rhs_e),
                        #("pml_rhs_h", pml_rhs_h),
                        #("pml_rhs_p", pml_rhs_p),
                        #("pml_rhs_q", pml_rhs_q),
                        #("max_rhs_e", max_rhs_e),
                        #("max_rhs_h", max_rhs_h),
                        #("max_rhs_p", max_rhs_p),
                        #("max_rhs_q", max_rhs_q),
                    ],
                    time=t,
                    step=step)
                visf.close()

            fields = stepper(fields, t, dt, rhs)

        _, _, energies_data = logmgr.get_expr_dataset("W_el+W_mag")
        energies = [value for tick_nbr, value in energies_data]

        assert energies[-1] < max(energies) * 1e-2

    finally:
        logmgr.close()

        if write_output:
            vis.close()
예제 #4
0
def test_kv_with_no_charge():
    from random import seed
    seed(0)

    from pyrticle.units import SIUnitsWithNaturalConstants
    units = SIUnitsWithNaturalConstants()

    # discretization setup ----------------------------------------------------
    from hedge.mesh import make_cylinder_mesh
    from hedge.backends import guess_run_context

    rcon = guess_run_context([])

    tube_length = 100*units.MM
    mesh = make_cylinder_mesh(radius=25*units.MM, height=tube_length, periodic=True)

    discr = rcon.make_discretization(mesh, order=3)

    dt = discr.dt_factor(units.VACUUM_LIGHT_SPEED()) / 2
    final_time = 1*units.M/units.VACUUM_LIGHT_SPEED()
    nsteps = int(final_time/dt)+1
    dt = final_time/nsteps

    # particles setup ---------------------------------------------------------
    from pyrticle.cloud import PicMethod
    from pyrticle.deposition.shape import ShapeFunctionDepositor
    from pyrticle.pusher import MonomialParticlePusher

    method = PicMethod(discr, units,
            ShapeFunctionDepositor(),
            MonomialParticlePusher(),
            3, 3)

    nparticles = 10000
    cloud_charge = 1e-9 * units.C
    electrons_per_particle = cloud_charge/nparticles/units.EL_CHARGE

    el_energy = 5.2e6 * units.EV
    gamma = el_energy/units.EL_REST_ENERGY()
    beta = (1-1/gamma**2)**0.5

    from pyrticle.distribution import KVZIntervalBeam
    beam = KVZIntervalBeam(units,
            total_charge=0,
            p_charge=0,
            p_mass=electrons_per_particle*units.EL_MASS,
            radii=2*[2.5*units.MM],
            emittances=2*[5 * units.MM * units.MRAD],
            z_length=5*units.MM,
            z_pos=10*units.MM,
            beta=beta)

    state = method.make_state()
    method.add_particles(state, beam.generate_particles(), nparticles)

    # diagnostics setup -------------------------------------------------------
    from pytools.log import LogManager
    from pyrticle.log import add_beam_quantities, StateObserver
    observer = StateObserver(method, None)
    logmgr = LogManager(mode="w")
    add_beam_quantities(logmgr, observer, axis=0, beam_axis=2)

    from pyrticle.distribution import KVPredictedRadius
    logmgr.add_quantity(KVPredictedRadius(dt,
        beam_v=beta*units.VACUUM_LIGHT_SPEED(),
        predictor=beam.get_rms_predictor(axis=0),
        suffix="x_rms"))
    logmgr.add_quantity(KVPredictedRadius(dt,
        beam_v=beta*units.VACUUM_LIGHT_SPEED(),
        predictor=beam.get_total_predictor(axis=0),
        suffix="x_total"))

    # timestep loop -----------------------------------------------------------
    vel = method.velocities(state)
    from hedge.tools import join_fields
    def rhs(t, y):
        return join_fields([
            vel,
            0*vel,
            0, # drecon
            ])

    from hedge.timestep.runge_kutta import LSRK4TimeStepper
    stepper = LSRK4TimeStepper()
    t = 0

    from pyrticle.cloud import TimesteppablePicState
    ts_state = TimesteppablePicState(method, state)

    for step in xrange(nsteps):
        observer.set_fields_and_state(None, ts_state.state)

        logmgr.tick()

        ts_state = stepper(ts_state, t, dt, rhs)
        method.upkeep(ts_state.state)

        t += dt

    logmgr.tick()

    _, _, err_table = logmgr.get_expr_dataset("(rx_rms-rx_rms_theory)/rx_rms_theory")
    rel_max_rms_error = max(err for step, err in err_table)
    assert rel_max_rms_error < 0.01