Beispiel #1
0
    def op_template(self, w=None):
        from hedge.tools import count_subset
        fld_cnt = count_subset(self.get_eh_subset())
        if w is None:
            from hedge.optemplate import make_sym_vector
            w = make_sym_vector("w", fld_cnt + 2 * self.dimensions)

        from hedge.tools import join_fields
        return join_fields(MaxwellOperator.op_template(self, w[:fld_cnt]),
                           numpy.zeros((2 * self.dimensions, ),
                                       dtype=object)) + self.pml_local_op(w)
Beispiel #2
0
    def op_template(self, w=None):
        from hedge.tools import count_subset
        fld_cnt = count_subset(self.get_eh_subset())
        if w is None:
            from hedge.optemplate import make_vector_field
            w = make_vector_field("w", fld_cnt+2*self.dimensions)

        from hedge.tools import join_fields
        return join_fields(
                MaxwellOperator.op_template(self, w[:fld_cnt]),
                numpy.zeros((2*self.dimensions,), dtype=object)
                ) + self.pml_local_op(w)
Beispiel #3
0
def test_efield_vs_gauss_law():
    from hedge.mesh.generator import \
            make_box_mesh, \
            make_cylinder_mesh
    from math import sqrt, pi
    from pytools.arithmetic_container import \
            ArithmeticList, join_fields
    from random import seed
    from pytools.stopwatch import Job

    from pyrticle.units import SIUnitsWithNaturalConstants
    units = SIUnitsWithNaturalConstants()

    seed(0)

    nparticles = 10000
    beam_radius = 2.5 * units.MM
    emittance = 5 * units.MM * units.MRAD
    final_time = 0.1 * units.M / units.VACUUM_LIGHT_SPEED()
    field_dump_interval = 1
    tube_length = 20 * units.MM

    # discretization setup ----------------------------------------------------
    from pyrticle.geometry import make_cylinder_with_fine_core
    mesh = make_cylinder_with_fine_core(
        r=10 * beam_radius,
        inner_r=1 * beam_radius,
        min_z=0,
        max_z=tube_length,
        max_volume_inner=10 * units.MM**3,
        max_volume_outer=100 * units.MM**3,
        radial_subdiv=10,
    )

    from hedge.backends import guess_run_context
    rcon = guess_run_context([])
    discr = rcon.make_discretization(mesh, order=3)

    from hedge.models.em import MaxwellOperator
    max_op = MaxwellOperator(epsilon=units.EPSILON0, mu=units.MU0, flux_type=1)

    from hedge.models.nd_calculus import DivergenceOperator
    div_op = DivergenceOperator(discr.dimensions)

    # 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)

    # particle ic ---------------------------------------------------------
    cloud_charge = -1e-9 * units.C
    electrons_per_particle = abs(cloud_charge / nparticles / units.EL_CHARGE)

    el_energy = 10 * units.EL_REST_ENERGY()
    el_lorentz_gamma = el_energy / units.EL_REST_ENERGY()
    beta = (1 - 1 / el_lorentz_gamma**2)**0.5
    gamma = 1 / sqrt(1 - beta**2)

    from pyrticle.distribution import KVZIntervalBeam
    beam = KVZIntervalBeam(units,
                           total_charge=cloud_charge,
                           p_charge=cloud_charge / nparticles,
                           p_mass=electrons_per_particle * units.EL_MASS,
                           radii=2 * [beam_radius],
                           emittances=2 * [5 * units.MM * units.MRAD],
                           z_length=tube_length,
                           z_pos=tube_length / 2,
                           beta=beta)

    state = method.make_state()

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

    # field ic ----------------------------------------------------------------
    from pyrticle.cloud import guess_shape_bandwidth
    guess_shape_bandwidth(method, state, 2)

    from pyrticle.cloud import compute_initial_condition

    from hedge.data import ConstantGivenFunction
    fields = compute_initial_condition(rcon,
                                       discr,
                                       method,
                                       state,
                                       maxwell_op=max_op,
                                       potential_bc=ConstantGivenFunction())

    # check against theory ----------------------------------------------------
    q_per_unit_z = cloud_charge / beam.z_length

    class TheoreticalEField:
        shape = (3, )

        def __call__(self, x, el):
            r = la.norm(x[:2])
            if r >= max(beam.radii):
                xy_unit = x / r
                xy_unit[2] = 0
                return xy_unit * ((q_per_unit_z) /
                                  (2 * pi * r * max_op.epsilon))
            else:
                return numpy.zeros((3, ))

    def theory_indicator(x, el):
        r = la.norm(x[:2])
        if r >= max(beam.radii):
            return 1
        else:
            return 0

    from hedge.tools import join_fields, to_obj_array
    e_theory = to_obj_array(
        discr.interpolate_volume_function(TheoreticalEField()))
    theory_ind = discr.interpolate_volume_function(theory_indicator)

    e_field, h_field = max_op.split_eh(fields)
    restricted_e = join_fields(*[e_i * theory_ind for e_i in e_field])

    def l2_error(field, true):
        return discr.norm(field - true) / discr.norm(true)

    outer_l2 = l2_error(restricted_e, e_theory)
    assert outer_l2 < 0.08

    if False:
        visf = vis.make_file("e_comparison")
        mesh_scalars, mesh_vectors = \
                method.add_to_vis(vis, visf)
        vis.add_data(visf, [
            ("e", restricted_e),
            ("e_theory", e_theory),
        ] + mesh_vectors + mesh_scalars)
        visf.close()
Beispiel #4
0
def test_efield_vs_gauss_law():
    from hedge.mesh.generator import \
            make_box_mesh, \
            make_cylinder_mesh
    from math import sqrt, pi
    from pytools.arithmetic_container import \
            ArithmeticList, join_fields
    from random import seed
    from pytools.stopwatch import Job

    from pyrticle.units import SIUnitsWithNaturalConstants
    units = SIUnitsWithNaturalConstants()

    seed(0)

    nparticles = 10000
    beam_radius = 2.5 * units.MM
    emittance = 5 * units.MM * units.MRAD
    final_time = 0.1*units.M/units.VACUUM_LIGHT_SPEED()
    field_dump_interval = 1
    tube_length = 20*units.MM

    # discretization setup ----------------------------------------------------
    from pyrticle.geometry import make_cylinder_with_fine_core
    mesh = make_cylinder_with_fine_core(
            r=10*beam_radius, inner_r=1*beam_radius,
            min_z=0, max_z=tube_length,
            max_volume_inner=10*units.MM**3,
            max_volume_outer=100*units.MM**3,
            radial_subdiv=10,
            )

    from hedge.backends import guess_run_context
    rcon = guess_run_context([])
    discr = rcon.make_discretization(mesh, order=3)

    from hedge.models.em import MaxwellOperator
    max_op = MaxwellOperator(
            epsilon=units.EPSILON0,
            mu=units.MU0,
            flux_type=1)

    from hedge.models.nd_calculus import DivergenceOperator
    div_op = DivergenceOperator(discr.dimensions)

    # 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)

    # particle ic ---------------------------------------------------------
    cloud_charge = -1e-9 * units.C
    electrons_per_particle = abs(cloud_charge/nparticles/units.EL_CHARGE)

    el_energy = 10*units.EL_REST_ENERGY()
    el_lorentz_gamma = el_energy/units.EL_REST_ENERGY()
    beta = (1-1/el_lorentz_gamma**2)**0.5
    gamma = 1/sqrt(1-beta**2)

    from pyrticle.distribution import KVZIntervalBeam
    beam = KVZIntervalBeam(units, total_charge=cloud_charge,
            p_charge=cloud_charge/nparticles,
            p_mass=electrons_per_particle*units.EL_MASS,
            radii=2*[beam_radius],
            emittances=2*[5 * units.MM * units.MRAD],
            z_length=tube_length,
            z_pos=tube_length/2,
            beta=beta)

    state = method.make_state()

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

    # field ic ----------------------------------------------------------------
    from pyrticle.cloud import guess_shape_bandwidth
    guess_shape_bandwidth(method, state, 2)

    from pyrticle.cloud import compute_initial_condition

    from hedge.data import ConstantGivenFunction
    fields = compute_initial_condition(
            rcon,
            discr, method, state, maxwell_op=max_op,
            potential_bc=ConstantGivenFunction())

    # check against theory ----------------------------------------------------
    q_per_unit_z = cloud_charge/beam.z_length
    class TheoreticalEField:
        shape = (3,)

        def __call__(self, x, el):
            r = la.norm(x[:2])
            if r >= max(beam.radii):
                xy_unit = x/r
                xy_unit[2] = 0
                return xy_unit*((q_per_unit_z)
                        /
                        (2*pi*r*max_op.epsilon))
            else:
                return numpy.zeros((3,))

    def theory_indicator(x, el):
        r = la.norm(x[:2])
        if r >= max(beam.radii):
            return 1
        else:
            return 0

    from hedge.tools import join_fields, to_obj_array
    e_theory = to_obj_array(discr.interpolate_volume_function(TheoreticalEField()))
    theory_ind = discr.interpolate_volume_function(theory_indicator)

    e_field, h_field = max_op.split_eh(fields)
    restricted_e = join_fields(*[e_i * theory_ind for e_i in e_field])

    def l2_error(field, true):
        return discr.norm(field-true)/discr.norm(true)

    outer_l2 = l2_error(restricted_e, e_theory)
    assert outer_l2 < 0.08

    if False:
        visf = vis.make_file("e_comparison")
        mesh_scalars, mesh_vectors = \
                method.add_to_vis(vis, visf)
        vis.add_data(visf, [
            ("e", restricted_e),
            ("e_theory", e_theory),
            ]
            + mesh_vectors
            + mesh_scalars
            )
        visf.close()
Beispiel #5
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 def __init__(self, *args, **kwargs):
     self.add_decay = kwargs.pop("add_decay", True)
     MaxwellOperator.__init__(self, *args, **kwargs)
Beispiel #6
0
 def bind(self, discr, coefficients):
     return MaxwellOperator.bind(self, discr,
             sigma=coefficients.sigma,
             sigma_prime=coefficients.sigma_prime,
             tau=coefficients.tau)
Beispiel #7
0
def run_setup(units, casename, setup, discr, pusher, visualize=False):
    from hedge.timestep.runge_kutta import LSRK4TimeStepper
    from hedge.visualization import SiloVisualizer
    from hedge.models.em import MaxwellOperator

    vis = SiloVisualizer(discr)

    from pyrticle.cloud import PicMethod
    from pyrticle.deposition.shape import ShapeFunctionDepositor
    method = PicMethod(discr,
                       units,
                       ShapeFunctionDepositor(),
                       pusher(),
                       3,
                       3,
                       debug=set(["verbose_vis"]))

    e, h = setup.fields(discr)
    b = units.MU0 * h

    init_positions = setup.positions(0)
    init_velocities = setup.velocities(0)

    nparticles = len(init_positions)

    state = method.make_state()
    method.add_particles(
        state,
        zip(
            init_positions,
            init_velocities,
            nparticles * [setup.charge],
            nparticles * [units.EL_MASS],
        ), nparticles)

    final_time = setup.final_time()
    nsteps = setup.nsteps()
    dt = final_time / nsteps

    # timestepping ------------------------------------------------------------
    from hedge.models.em import MaxwellOperator
    max_op = MaxwellOperator(epsilon=units.EPSILON0, mu=units.MU0, flux_type=1)

    fields = max_op.assemble_eh(e, h)

    from pyrticle.cloud import \
            FieldToParticleRhsCalculator, \
            ParticleRhsCalculator
    p_rhs_calculator = ParticleRhsCalculator(method, max_op)
    f2p_rhs_calculator = FieldToParticleRhsCalculator(method, max_op)

    def rhs(t, ts_state):
        return (p_rhs_calculator(t, lambda: fields, lambda: ts_state.state) +
                f2p_rhs_calculator(t, lambda: fields, lambda: ts_state.state))

    stepper = LSRK4TimeStepper()
    t = 0

    bbox = discr.mesh.bounding_box()
    z_period = bbox[1][2] - bbox[0][2]

    def check_result():
        from hedge.tools import cross

        deriv_dt = 1e-12

        dim = discr.dimensions
        true_x = setup.positions(t)
        true_v = setup.velocities(t)
        true_f = [(p2 - p1) / (2 * deriv_dt) for p1, p2 in zip(
            setup.momenta(t - deriv_dt), setup.momenta(t + deriv_dt))]

        state = ts_state.state

        from pyrticle.tools import NumberShiftableVector
        vis_info = state.vis_listener.particle_vis_map
        sim_x = state.positions
        sim_v = method.velocities(state)
        sim_f = NumberShiftableVector.unwrap(vis_info["mag_force"] +
                                             vis_info["el_force"])
        sim_el_f = NumberShiftableVector.unwrap(vis_info["el_force"])
        sim_mag_f = NumberShiftableVector.unwrap(vis_info["mag_force"])

        local_e = setup.e()
        local_b = units.MU0 * setup.h()

        x_err = 0
        v_err = 0
        f_err = 0

        for i in range(len(state)):
            #real_f = numpy.array(cross(sim_v, setup.charge*local_b)) + setup.charge*local_e

            my_true_x = true_x[i]
            my_true_x[2] = my_true_x[2] % z_period
            if False and i == 0:
                #print "particle %d" % i
                print "pos:", la.norm(true_x[i] - sim_x[i]) / la.norm(
                    true_x[i])
                #print "vel:", la.norm(true_v[i]-sim_v[i])/la.norm(true_v[i])
                #print "force:", la.norm(true_f[i]-sim_f[i])/la.norm(true_f[i])
                print "pos:", true_x[i], sim_x[i]
                #print "vel:", true_v[i], sim_v[i]
                #print "force:", true_f[i], sim_f[i]
                #print "forces%d:..." % i, sim_el_f[i], sim_mag_f[i]
                #print "acc%d:" % i, la.norm(a-sim_a)
                #u = numpy.vstack((v, sim_v, f, sim_f, real_f))
                #print "acc%d:\n%s" % (i, u)
                #raw_input()

            def rel_err(sim, true):
                return la.norm(true - sim) / la.norm(true)

            x_err = max(x_err, rel_err(sim_x[i], my_true_x))
            v_err = max(v_err, rel_err(sim_v[i], true_v[i]))
            f_err = max(f_err, rel_err(sim_f[i], true_f[i]))

        return x_err, v_err, f_err

    # make sure verbose-vis fields are filled
    from pyrticle.cloud import TimesteppablePicState
    ts_state = TimesteppablePicState(method, state)
    del state

    rhs(t, ts_state)

    errors = (0, 0, 0)

    for step in xrange(nsteps):
        if step % int(setup.nsteps() / 300) == 0:
            errors = tuple(
                max(old_err, new_err)
                for old_err, new_err in zip(errors, check_result()))

            if visualize:
                visf = vis.make_file("%s-%04d" % (casename, step))

                method.add_to_vis(vis, visf, ts_state.state, time=t, step=step)

                if True:
                    vis.add_data(visf, [
                        ("e", e),
                        ("h", h),
                    ],
                                 time=t,
                                 step=step)
                else:
                    vis.add_data(visf, [], time=t, step=step)
                visf.close()

        method.upkeep(ts_state.state)

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

        t += dt

    assert errors[0] < 2e-12, casename + "-pos"
    assert errors[1] < 2e-13, casename + "-vel"
    assert errors[2] < 2e-4, casename + "-acc"

    vis.close()
Beispiel #8
0
def main(write_output=True, allow_features=None, flux_type_arg=1, bdry_flux_type_arg=None, extra_discr_args={}):
    from hedge.mesh.generator import make_cylinder_mesh, make_box_mesh
    from hedge.tools import EOCRecorder, to_obj_array
    from math import sqrt, pi
    from analytic_solutions import (
        check_time_harmonic_solution,
        RealPartAdapter,
        SplitComplexAdapter,
        CylindricalFieldAdapter,
        CylindricalCavityMode,
        RectangularWaveguideMode,
        RectangularCavityMode,
    )
    from hedge.models.em import MaxwellOperator

    from hedge.backends import guess_run_context

    rcon = guess_run_context(allow_features)

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

    eoc_rec = EOCRecorder()

    cylindrical = False
    periodic = False

    if cylindrical:
        R = 1
        d = 2
        mode = CylindricalCavityMode(m=1, n=1, p=1, radius=R, height=d, epsilon=epsilon, mu=mu)
        r_sol = CylindricalFieldAdapter(RealPartAdapter(mode))
        c_sol = SplitComplexAdapter(CylindricalFieldAdapter(mode))

        if rcon.is_head_rank:
            mesh = make_cylinder_mesh(radius=R, height=d, max_volume=0.01)
    else:
        if periodic:
            mode = RectangularWaveguideMode(epsilon, mu, (3, 2, 1))
            periodicity = (False, False, True)
        else:
            periodicity = None
        mode = RectangularCavityMode(epsilon, mu, (1, 2, 2))

        if rcon.is_head_rank:
            mesh = make_box_mesh(max_volume=0.001, periodicity=periodicity)

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

    for order in [4, 5, 6]:
        # for order in [1,2,3,4,5,6]:
        extra_discr_args.setdefault("debug", []).extend(["cuda_no_plan", "cuda_dump_kernels"])

        op = MaxwellOperator(epsilon, mu, flux_type=flux_type_arg, bdry_flux_type=bdry_flux_type_arg)

        discr = rcon.make_discretization(mesh_data, order=order, tune_for=op.op_template(), **extra_discr_args)

        from hedge.visualization import VtkVisualizer

        if write_output:
            vis = VtkVisualizer(discr, rcon, "em-%d" % order)

        mode.set_time(0)

        def get_true_field():
            return discr.convert_volume(
                to_obj_array(mode(discr).real.astype(discr.default_scalar_type).copy()), kind=discr.compute_kind
            )

        fields = get_true_field()

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

        from hedge.timestep.runge_kutta import LSRK4TimeStepper

        stepper = LSRK4TimeStepper(dtype=discr.default_scalar_type, rcon=rcon)
        # from hedge.timestep.dumka3 import Dumka3TimeStepper
        # stepper = Dumka3TimeStepper(3, dtype=discr.default_scalar_type, rcon=rcon)

        # 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"])

        # timestep loop -------------------------------------------------------
        rhs = op.bind(discr)
        final_time = 0.5e-9

        try:
            from hedge.timestep import times_and_steps

            step_it = times_and_steps(
                final_time=final_time,
                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 % 50 == 0 and write_output:
                    sub_timer = vis_timer.start_sub_timer()
                    e, h = op.split_eh(fields)
                    visf = vis.make_file("em-%d-%04d" % (order, step))
                    vis.add_data(
                        visf,
                        [("e", discr.convert_volume(e, kind="numpy")), ("h", discr.convert_volume(h, kind="numpy"))],
                        time=t,
                        step=step,
                    )
                    visf.close()
                    sub_timer.stop().submit()

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

            mode.set_time(final_time)

            eoc_rec.add_data_point(order, discr.norm(fields - get_true_field()))

        finally:
            if write_output:
                vis.close()

            logmgr.close()
            discr.close()

        if rcon.is_head_rank:
            print
            print eoc_rec.pretty_print("P.Deg.", "L2 Error")

    assert eoc_rec.estimate_order_of_convergence()[0, 1] > 6
Beispiel #9
0
 def __init__(self, *args, **kwargs):
     self.add_decay = kwargs.pop("add_decay", True)
     MaxwellOperator.__init__(self, *args, **kwargs)
Beispiel #10
0
 def bind(self, discr, coefficients):
     return MaxwellOperator.bind(self,
                                 discr,
                                 sigma=coefficients.sigma,
                                 sigma_prime=coefficients.sigma_prime,
                                 tau=coefficients.tau)
Beispiel #11
0
def main(write_output=True, allow_features=None):
    from hedge.timestep import RK4TimeStepper
    from hedge.mesh import make_ball_mesh, make_cylinder_mesh, make_box_mesh
    from hedge.visualization import \
            VtkVisualizer, \
            SiloVisualizer, \
            get_rank_partition
    from math import sqrt, pi

    from hedge.backends import guess_run_context
    rcon = guess_run_context(allow_features)

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

    dims = 3

    if rcon.is_head_rank:
        if dims == 2:
            from hedge.mesh import make_rect_mesh
            mesh = make_rect_mesh(a=(-10.5, -1.5), b=(10.5, 1.5), max_area=0.1)
        elif dims == 3:
            from hedge.mesh import make_box_mesh
            mesh = make_box_mesh(a=(-10.5, -1.5, -1.5),
                                 b=(10.5, 1.5, 1.5),
                                 max_volume=0.1)

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

    #for order in [1,2,3,4,5,6]:
    discr = rcon.make_discretization(mesh_data, order=3)

    if write_output:
        vis = VtkVisualizer(discr, rcon, "dipole")

    from analytic_solutions import DipoleFarField, SphericalFieldAdapter
    from hedge.data import ITimeDependentGivenFunction

    sph_dipole = DipoleFarField(
        q=1,  #C
        d=1 / 39,
        omega=2 * pi * 1e8,
        epsilon=epsilon0,
        mu=mu0,
    )
    cart_dipole = SphericalFieldAdapter(sph_dipole)

    class PointDipoleSource(ITimeDependentGivenFunction):
        def __init__(self):
            from pyrticle.tools import CInfinityShapeFunction
            sf = CInfinityShapeFunction(0.1 * sph_dipole.wavelength,
                                        discr.dimensions)
            self.num_sf = discr.interpolate_volume_function(
                lambda x, el: sf(x))
            self.vol_0 = discr.volume_zeros()

        def volume_interpolant(self, t, discr):
            from hedge.tools import make_obj_array
            return make_obj_array([
                self.vol_0, self.vol_0,
                sph_dipole.source_modulation(t) * self.num_sf
            ])

    from hedge.mesh import TAG_ALL, TAG_NONE
    if dims == 2:
        from hedge.models.em import TMMaxwellOperator as MaxwellOperator
    else:
        from hedge.models.em import MaxwellOperator

    op = MaxwellOperator(
        epsilon,
        mu,
        flux_type=1,
        pec_tag=TAG_NONE,
        absorb_tag=TAG_ALL,
        current=PointDipoleSource(),
    )

    fields = op.assemble_eh(discr=discr)

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

    stepper = RK4TimeStepper()

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

    if write_output:
        log_file_name = "dipole.dat"
    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)

    from pytools.log import PushLogQuantity
    relerr_e_q = PushLogQuantity("relerr_e", "1",
                                 "Relative error in masked E-field")
    relerr_h_q = PushLogQuantity("relerr_h", "1",
                                 "Relative error in masked H-field")
    logmgr.add_quantity(relerr_e_q)
    logmgr.add_quantity(relerr_h_q)

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

    if write_output:
        point_timeseries = [(open("b-x%d-vs-time.dat" % i,
                                  "w"), open("b-x%d-vs-time-true.dat" % i,
                                             "w"),
                             discr.get_point_evaluator(
                                 numpy.array([i, 0, 0][:dims],
                                             dtype=discr.default_scalar_type)))
                            for i in range(1, 5)]

    # timestep loop -------------------------------------------------------
    mask = discr.interpolate_volume_function(sph_dipole.far_field_mask)

    def apply_mask(field):
        from hedge.tools import log_shape
        ls = log_shape(field)
        result = discr.volume_empty(ls)
        from pytools import indices_in_shape
        for i in indices_in_shape(ls):
            result[i] = mask * field[i]

        return result

    rhs = op.bind(discr)

    t = 0
    try:
        from hedge.timestep import times_and_steps
        step_it = times_and_steps(
            final_time=1e-8,
            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 write_output and step % 10 == 0:
                sub_timer = vis_timer.start_sub_timer()
                e, h = op.split_eh(fields)
                sph_dipole.set_time(t)
                true_e, true_h = op.split_eh(
                    discr.interpolate_volume_function(cart_dipole))
                visf = vis.make_file("dipole-%04d" % step)

                mask_e = apply_mask(e)
                mask_h = apply_mask(h)
                mask_true_e = apply_mask(true_e)
                mask_true_h = apply_mask(true_h)

                from pyvisfile.silo import DB_VARTYPE_VECTOR
                vis.add_data(visf, [("e", e), ("h", h), ("true_e", true_e),
                                    ("true_h", true_h), ("mask_e", mask_e),
                                    ("mask_h", mask_h),
                                    ("mask_true_e", mask_true_e),
                                    ("mask_true_h", mask_true_h)],
                             time=t,
                             step=step)
                visf.close()
                sub_timer.stop().submit()

                from hedge.tools import relative_error
                relerr_e_q.push_value(
                    relative_error(discr.norm(mask_e - mask_true_e),
                                   discr.norm(mask_true_e)))
                relerr_h_q.push_value(
                    relative_error(discr.norm(mask_h - mask_true_h),
                                   discr.norm(mask_true_h)))

                if write_output:
                    for outf_num, outf_true, evaluator in point_timeseries:
                        for outf, ev_h in zip([outf_num, outf_true],
                                              [h, true_h]):
                            outf.write("%g\t%g\n" %
                                       (t, op.mu * evaluator(ev_h[1])))
                            outf.flush()

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

    finally:
        if write_output:
            vis.close()

        logmgr.save()
        discr.close()
Beispiel #12
0
def run_setup(units, casename, setup, discr, pusher, visualize=False):
    from hedge.timestep.runge_kutta import LSRK4TimeStepper
    from hedge.visualization import SiloVisualizer
    from hedge.models.em import MaxwellOperator

    vis = SiloVisualizer(discr)

    from pyrticle.cloud import PicMethod
    from pyrticle.deposition.shape import ShapeFunctionDepositor
    method = PicMethod(discr, units, 
            ShapeFunctionDepositor(),
            pusher(),
            3, 3, debug=set(["verbose_vis"]))

    e, h = setup.fields(discr)
    b = units.MU0 * h

    init_positions = setup.positions(0)
    init_velocities = setup.velocities(0)

    nparticles = len(init_positions)

    state = method.make_state()
    method.add_particles(state,
            zip(init_positions, init_velocities, 
                nparticles * [setup.charge],
                nparticles  * [units.EL_MASS],
                ),
            nparticles)

    final_time = setup.final_time()
    nsteps = setup.nsteps()
    dt = final_time/nsteps

    # timestepping ------------------------------------------------------------
    from hedge.models.em import MaxwellOperator
    max_op = MaxwellOperator(
            epsilon=units.EPSILON0, 
            mu=units.MU0, 
            flux_type=1)

    fields = max_op.assemble_eh(e, h)

    from pyrticle.cloud import \
            FieldToParticleRhsCalculator, \
            ParticleRhsCalculator
    p_rhs_calculator = ParticleRhsCalculator(method, max_op)
    f2p_rhs_calculator = FieldToParticleRhsCalculator(method, max_op)

    def rhs(t, ts_state):
        return (p_rhs_calculator(t, lambda: fields, lambda: ts_state.state)
                + f2p_rhs_calculator(t, lambda: fields, lambda: ts_state.state))

    stepper = LSRK4TimeStepper()
    t = 0

    bbox = discr.mesh.bounding_box()
    z_period = bbox[1][2] - bbox[0][2]

    def check_result():
        from hedge.tools import cross

        deriv_dt = 1e-12

        dim = discr.dimensions
        true_x = setup.positions(t)
        true_v = setup.velocities(t)
        true_f = [(p2-p1)/(2*deriv_dt)
                for p1, p2 in zip(setup.momenta(t-deriv_dt), setup.momenta(t+deriv_dt))]

        state = ts_state.state

        from pyrticle.tools import NumberShiftableVector
        vis_info = state.vis_listener.particle_vis_map
        sim_x = state.positions
        sim_v = method.velocities(state)
        sim_f = NumberShiftableVector.unwrap(
                vis_info["mag_force"] + vis_info["el_force"])
        sim_el_f = NumberShiftableVector.unwrap(vis_info["el_force"])
        sim_mag_f = NumberShiftableVector.unwrap(vis_info["mag_force"])

        local_e = setup.e()
        local_b = units.MU0 * setup.h()

        x_err = 0
        v_err = 0
        f_err = 0

        for i in range(len(state)):
            #real_f = numpy.array(cross(sim_v, setup.charge*local_b)) + setup.charge*local_e

            my_true_x = true_x[i]
            my_true_x[2] = my_true_x[2] % z_period
            if False and i == 0:
                #print "particle %d" % i
                print "pos:", la.norm(true_x[i]-sim_x[i])/la.norm(true_x[i])
                #print "vel:", la.norm(true_v[i]-sim_v[i])/la.norm(true_v[i])
                #print "force:", la.norm(true_f[i]-sim_f[i])/la.norm(true_f[i])
                print "pos:", true_x[i], sim_x[i]
                #print "vel:", true_v[i], sim_v[i]
                #print "force:", true_f[i], sim_f[i]
                #print "forces%d:..." % i, sim_el_f[i], sim_mag_f[i]
                #print "acc%d:" % i, la.norm(a-sim_a)
                #u = numpy.vstack((v, sim_v, f, sim_f, real_f))
                #print "acc%d:\n%s" % (i, u)
                #raw_input()

            def rel_err(sim, true):
                return la.norm(true-sim)/la.norm(true)

            x_err = max(x_err, rel_err(sim_x[i], my_true_x))
            v_err = max(v_err, rel_err(sim_v[i], true_v[i]))
            f_err = max(f_err, rel_err(sim_f[i], true_f[i]))

        return x_err, v_err, f_err

    # make sure verbose-vis fields are filled
    from pyrticle.cloud import TimesteppablePicState
    ts_state = TimesteppablePicState(method, state)
    del state

    rhs(t, ts_state)

    errors = (0, 0, 0)

    for step in xrange(nsteps):
        if step % int(setup.nsteps()/300) == 0:
            errors = tuple(
                    max(old_err, new_err) 
                    for old_err, new_err in zip(errors, check_result()))

            if visualize:
                visf = vis.make_file("%s-%04d" % (casename, step))

                method.add_to_vis(vis, visf, ts_state.state, time=t, step=step)

                if True:
                    vis.add_data(visf, [ ("e", e), ("h", h), ],
                            time=t, step=step)
                else:
                    vis.add_data(visf, [], time=t, step=step)
                visf.close()

        method.upkeep(ts_state.state)

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

        t += dt

    assert errors[0] < 2e-12, casename+"-pos"
    assert errors[1] < 2e-13, casename+"-vel"
    assert errors[2] < 2e-4, casename+"-acc"

    vis.close()
Beispiel #13
0
    def __init__(self):
        from pyrticle.units import SIUnitsWithNaturalConstants
        self.units = units = SIUnitsWithNaturalConstants()

        ui = PICCPyUserInterface(units)
        setup = self.setup = ui.gather()

        from pytools.log import LogManager
        import os.path
        self.logmgr = LogManager(os.path.join(setup.output_path, "pic.dat"),
                                 "w")

        from hedge.backends import guess_run_context
        self.rcon = guess_run_context([])

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

        self.discr = discr = \
                self.rcon.make_discretization(mesh,
                        order=setup.element_order,
                        debug=setup.dg_debug)

        self.logmgr.set_constant("elements_total", len(setup.mesh.elements))
        self.logmgr.set_constant("elements_local", len(mesh.elements))
        self.logmgr.set_constant("element_order", setup.element_order)

        # em operator ---------------------------------------------------------
        maxwell_kwargs = {
            "epsilon": units.EPSILON0,
            "mu": units.MU0,
            "flux_type": setup.maxwell_flux_type,
            "bdry_flux_type": setup.maxwell_bdry_flux_type
        }

        if discr.dimensions == 3:
            from hedge.models.em import MaxwellOperator
            self.maxwell_op = MaxwellOperator(**maxwell_kwargs)
        elif discr.dimensions == 2:
            from hedge.models.em import TEMaxwellOperator
            self.maxwell_op = TEMaxwellOperator(**maxwell_kwargs)
        else:
            raise ValueError, "invalid mesh dimension"

        if setup.chi is not None:
            from pyrticle.hyperbolic import ECleaningMaxwellOperator
            self.maxwell_op = ECleaningMaxwellOperator(
                self.maxwell_op, chi=setup.chi, phi_decay=setup.phi_decay)

            if setup.phi_filter is not None:
                from pyrticle.hyperbolic import PhiFilter
                from hedge.discretization import Filter, ExponentialFilterResponseFunction
                em_filters.append(
                    PhiFilter(
                        maxwell_op,
                        Filter(
                            discr,
                            ExponentialFilterResponseFunction(
                                *setup.phi_filter))))

        # timestepping setup --------------------------------------------------
        goal_dt = self.maxwell_op.estimate_timestep(discr) * setup.dt_scale
        self.nsteps = int(setup.final_time / goal_dt) + 1
        self.dt = setup.final_time / self.nsteps

        self.stepper = setup.timestepper_maker(self.dt)

        # particle setup ------------------------------------------------------
        from pyrticle.cloud import PicMethod, PicState, \
                optimize_shape_bandwidth, \
                guess_shape_bandwidth

        method = self.method = PicMethod(
            discr,
            units,
            setup.depositor,
            setup.pusher,
            dimensions_pos=setup.dimensions_pos,
            dimensions_velocity=setup.dimensions_velocity,
            debug=setup.debug)

        self.state = method.make_state()
        method.add_particles(self.state,
                             setup.distribution.generate_particles(),
                             setup.nparticles)

        self.total_charge = setup.nparticles * setup.distribution.mean()[2][0]
        if isinstance(setup.shape_bandwidth, str):
            if setup.shape_bandwidth == "optimize":
                optimize_shape_bandwidth(
                    method, self.state,
                    setup.distribution.get_rho_interpolant(
                        discr, self.total_charge), setup.shape_exponent)
            elif setup.shape_bandwidth == "guess":
                guess_shape_bandwidth(method, self.state, setup.shape_exponent)
            else:
                raise ValueError, "invalid shape bandwidth setting '%s'" % (
                    setup.shape_bandwidth)
        else:
            from pyrticle._internal import PolynomialShapeFunction
            method.depositor.set_shape_function(
                self.state,
                PolynomialShapeFunction(
                    float(setup.shape_bandwidth),
                    method.mesh_data.dimensions,
                    setup.shape_exponent,
                ))

        # initial condition ---------------------------------------------------
        if "no_ic" in setup.debug:
            self.fields = self.maxwell_op.assemble_eh(discr=discr)
        else:
            from pyrticle.cloud import compute_initial_condition
            self.fields = compute_initial_condition(
                self.rcon,
                discr,
                method,
                self.state,
                maxwell_op=self.maxwell_op,
                potential_bc=setup.potential_bc,
                force_zero=False)

        # rhs calculators -----------------------------------------------------
        from pyrticle.cloud import \
                FieldRhsCalculator, \
                FieldToParticleRhsCalculator, \
                ParticleRhsCalculator, \
                ParticleToFieldRhsCalculator
        self.f_rhs_calculator = FieldRhsCalculator(self.method,
                                                   self.maxwell_op)
        self.p_rhs_calculator = ParticleRhsCalculator(self.method,
                                                      self.maxwell_op)
        self.f2p_rhs_calculator = FieldToParticleRhsCalculator(
            self.method, self.maxwell_op)
        self.p2f_rhs_calculator = ParticleToFieldRhsCalculator(
            self.method, self.maxwell_op)

        # instrumentation setup -----------------------------------------------
        self.add_instrumentation(self.logmgr)
Beispiel #14
0
def main(write_output=True,
         allow_features=None,
         flux_type_arg=1,
         bdry_flux_type_arg=None,
         extra_discr_args={}):
    from hedge.mesh.generator import make_cylinder_mesh, make_box_mesh
    from hedge.tools import EOCRecorder, to_obj_array
    from math import sqrt, pi  # noqa
    from analytic_solutions import (  # noqa
        RealPartAdapter, SplitComplexAdapter, CylindricalFieldAdapter,
        CylindricalCavityMode, RectangularWaveguideMode, RectangularCavityMode)
    from hedge.models.em import MaxwellOperator

    logging.basicConfig(level=logging.DEBUG)

    from hedge.backends import guess_run_context
    rcon = guess_run_context(allow_features)

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

    eoc_rec = EOCRecorder()

    cylindrical = False
    periodic = False

    if cylindrical:
        R = 1
        d = 2
        mode = CylindricalCavityMode(m=1,
                                     n=1,
                                     p=1,
                                     radius=R,
                                     height=d,
                                     epsilon=epsilon,
                                     mu=mu)
        # r_sol = CylindricalFieldAdapter(RealPartAdapter(mode))
        # c_sol = SplitComplexAdapter(CylindricalFieldAdapter(mode))

        if rcon.is_head_rank:
            mesh = make_cylinder_mesh(radius=R, height=d, max_volume=0.01)
    else:
        if periodic:
            mode = RectangularWaveguideMode(epsilon, mu, (3, 2, 1))
            periodicity = (False, False, True)
        else:
            periodicity = None
        mode = RectangularCavityMode(epsilon, mu, (1, 2, 2))

        if rcon.is_head_rank:
            mesh = make_box_mesh(max_volume=0.001, periodicity=periodicity)

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

    for order in [4, 5, 6]:
        #for order in [1,2,3,4,5,6]:
        extra_discr_args.setdefault("debug", []).extend(
            ["cuda_no_plan", "cuda_dump_kernels"])

        op = MaxwellOperator(epsilon,
                             mu,
                             flux_type=flux_type_arg,
                             bdry_flux_type=bdry_flux_type_arg)

        discr = rcon.make_discretization(mesh_data,
                                         order=order,
                                         tune_for=op.op_template(),
                                         **extra_discr_args)

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

        mode.set_time(0)

        def get_true_field():
            return discr.convert_volume(to_obj_array(
                mode(discr).real.astype(discr.default_scalar_type).copy()),
                                        kind=discr.compute_kind)

        fields = get_true_field()

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

        from hedge.timestep.runge_kutta import LSRK4TimeStepper
        stepper = LSRK4TimeStepper(dtype=discr.default_scalar_type, rcon=rcon)
        #from hedge.timestep.dumka3 import Dumka3TimeStepper
        #stepper = Dumka3TimeStepper(3, dtype=discr.default_scalar_type, rcon=rcon)

        # {{{ 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"])

        # }}}

        # {{{ timestep loop

        rhs = op.bind(discr)
        final_time = 0.5e-9

        try:
            from hedge.timestep import times_and_steps
            step_it = times_and_steps(
                final_time=final_time,
                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 % 50 == 0 and write_output:
                    sub_timer = vis_timer.start_sub_timer()
                    e, h = op.split_eh(fields)
                    visf = vis.make_file("em-%d-%04d" % (order, step))
                    vis.add_data(visf, [
                        ("e", discr.convert_volume(e, kind="numpy")),
                        ("h", discr.convert_volume(h, kind="numpy")),
                    ],
                                 time=t,
                                 step=step)
                    visf.close()
                    sub_timer.stop().submit()

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

            mode.set_time(final_time)

            eoc_rec.add_data_point(order,
                                   discr.norm(fields - get_true_field()))

        finally:
            if write_output:
                vis.close()

            logmgr.close()
            discr.close()

        if rcon.is_head_rank:
            print
            print eoc_rec.pretty_print("P.Deg.", "L2 Error")

        # }}}

    assert eoc_rec.estimate_order_of_convergence()[0, 1] > 6