Esempio n. 1
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def test_tangential_onb(actx_factory):
    actx = actx_factory()

    from meshmode.mesh.generation import generate_torus
    mesh = generate_torus(5, 2, order=3)

    discr = Discretization(
            actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(3))

    tob = sym.tangential_onb(mesh.ambient_dim)
    nvecs = tob.shape[1]

    # make sure tangential_onb is mutually orthogonal and normalized
    orth_check = bind(discr, sym.make_obj_array([
        np.dot(tob[:, i], tob[:, j]) - (1 if i == j else 0)
        for i in range(nvecs) for j in range(nvecs)])
        )(actx)

    for orth_i in orth_check:
        assert actx.to_numpy(
                actx.np.all(actx.np.abs(orth_i) < 1e-13)
                )

    # make sure tangential_onb is orthogonal to normal
    orth_check = bind(discr, sym.make_obj_array([
        np.dot(tob[:, i], sym.normal(mesh.ambient_dim).as_vector())
        for i in range(nvecs)])
        )(actx)

    for orth_i in orth_check:
        assert actx.to_numpy(
                actx.np.all(actx.np.abs(orth_i) < 1e-13)
                )
Esempio n. 2
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def test_tangential_onb(ctx_factory):
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)

    from meshmode.mesh.generation import generate_torus
    mesh = generate_torus(5, 2, order=3)

    discr = Discretization(
            cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(3))

    tob = sym.tangential_onb(mesh.ambient_dim)
    nvecs = tob.shape[1]

    # make sure tangential_onb is mutually orthogonal and normalized
    orth_check = bind(discr, sym.make_obj_array([
        np.dot(tob[:, i], tob[:, j]) - (1 if i == j else 0)
        for i in range(nvecs) for j in range(nvecs)])
        )(queue)

    for i, orth_i in enumerate(orth_check):
        assert (cl.clmath.fabs(orth_i) < 1e-13).get().all()

    # make sure tangential_onb is orthogonal to normal
    orth_check = bind(discr, sym.make_obj_array([
        np.dot(tob[:, i], sym.normal(mesh.ambient_dim).as_vector())
        for i in range(nvecs)])
        )(queue)

    for i, orth_i in enumerate(orth_check):
        assert (cl.clmath.fabs(orth_i) < 1e-13).get().all()
Esempio n. 3
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def test_tangential_onb(ctx_factory):
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)

    from meshmode.mesh.generation import generate_torus
    mesh = generate_torus(5, 2, order=3)

    discr = Discretization(cl_ctx, mesh,
                           InterpolatoryQuadratureSimplexGroupFactory(3))

    tob = sym.tangential_onb(mesh.ambient_dim)
    nvecs = tob.shape[1]

    # make sure tangential_onb is mutually orthogonal and normalized
    orth_check = bind(
        discr,
        sym.make_obj_array([
            np.dot(tob[:, i], tob[:, j]) - (1 if i == j else 0)
            for i in range(nvecs) for j in range(nvecs)
        ]))(queue)

    for i, orth_i in enumerate(orth_check):
        assert (cl.clmath.fabs(orth_i) < 1e-13).get().all()

    # make sure tangential_onb is orthogonal to normal
    orth_check = bind(
        discr,
        sym.make_obj_array([
            np.dot(tob[:, i],
                   sym.normal(mesh.ambient_dim).as_vector())
            for i in range(nvecs)
        ]))(queue)

    for i, orth_i in enumerate(orth_check):
        assert (cl.clmath.fabs(orth_i) < 1e-13).get().all()
Esempio n. 4
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def test_cost_model(ctx_factory, dim, use_target_specific_qbx):
    """Test that cost model gathering can execute successfully."""
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)
    actx = PyOpenCLArrayContext(queue)

    lpot_source = get_lpot_source(actx, dim).copy(
            _use_target_specific_qbx=use_target_specific_qbx,
            cost_model=CostModel())
    places = GeometryCollection(lpot_source)

    density_discr = places.get_discretization(places.auto_source.geometry)
    sigma = get_density(actx, density_discr)

    sigma_sym = sym.var("sigma")
    k_sym = LaplaceKernel(lpot_source.ambient_dim)

    sym_op_S = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)
    op_S = bind(places, sym_op_S)
    cost_S = op_S.get_modeled_cost(actx, sigma=sigma)
    assert len(cost_S) == 1

    sym_op_S_plus_D = (
            sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)
            + sym.D(k_sym, sigma_sym, qbx_forced_limit="avg"))
    op_S_plus_D = bind(places, sym_op_S_plus_D)
    cost_S_plus_D = op_S_plus_D.get_modeled_cost(actx, sigma=sigma)
    assert len(cost_S_plus_D) == 2
Esempio n. 5
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    def __call__(self, actx: PyOpenCLArrayContext, source_dd,
                 indices: BlockIndexRanges, **kwargs) -> BlockProxyPoints:
        from pytential import bind, sym
        source_dd = sym.as_dofdesc(source_dd)

        radii = bind(self.places,
                     sym.expansion_radii(self.ambient_dim,
                                         dofdesc=source_dd))(actx)
        center_int = bind(
            self.places,
            sym.expansion_centers(self.ambient_dim, -1,
                                  dofdesc=source_dd))(actx)
        center_ext = bind(
            self.places,
            sym.expansion_centers(self.ambient_dim, +1,
                                  dofdesc=source_dd))(actx)

        return super().__call__(actx,
                                source_dd,
                                indices,
                                expansion_radii=flatten(radii, actx),
                                center_int=flatten(center_int,
                                                   actx,
                                                   leaf_class=DOFArray),
                                center_ext=flatten(center_ext,
                                                   actx,
                                                   leaf_class=DOFArray),
                                **kwargs)
Esempio n. 6
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def test_unregularized_off_surface_fmm_vs_direct(ctx_factory):
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)
    actx = PyOpenCLArrayContext(queue)

    nelements = 300
    target_order = 8
    fmm_order = 4

    # {{{ geometry

    mesh = make_curve_mesh(WobblyCircle.random(8, seed=30),
                np.linspace(0, 1, nelements+1),
                target_order)

    from pytential.unregularized import UnregularizedLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    density_discr = Discretization(
            actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    direct = UnregularizedLayerPotentialSource(
            density_discr,
            fmm_order=False,
            )
    fmm = direct.copy(
            fmm_level_to_order=lambda kernel, kernel_args, tree, level: fmm_order)

    sigma = density_discr.zeros(actx) + 1

    fplot = FieldPlotter(np.zeros(2), extent=5, npoints=100)
    from pytential.target import PointsTarget
    ptarget = PointsTarget(fplot.points)

    from pytential import GeometryCollection
    places = GeometryCollection({
        "unregularized_direct": direct,
        "unregularized_fmm": fmm,
        "targets": ptarget})

    # }}}

    # {{{ check

    from sumpy.kernel import LaplaceKernel
    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=None)

    direct_fld_in_vol = bind(places, op,
            auto_where=("unregularized_direct", "targets"))(
                    actx, sigma=sigma)
    fmm_fld_in_vol = bind(places, op,
            auto_where=("unregularized_fmm", "targets"))(actx, sigma=sigma)

    err = actx.np.fabs(fmm_fld_in_vol - direct_fld_in_vol)
    linf_err = actx.to_numpy(err).max()
    print("l_inf error:", linf_err)

    assert linf_err < 5e-3
Esempio n. 7
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 def targets_from_sources(sign, dist, dim=2):
     nodes = dof_array_to_numpy(
         actx,
         bind(places, sym.nodes(dim, dofdesc=dd))(actx).as_vector(object))
     normals = dof_array_to_numpy(
         actx,
         bind(places, sym.normal(dim, dofdesc=dd))(actx).as_vector(object))
     return actx.from_numpy(nodes + normals * sign * dist)
Esempio n. 8
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    def map_int_g(self, expr):
        lpot_source = self.places.get_geometry(expr.source.geometry)
        source_discr = self.places.get_discretization(expr.source.geometry,
                                                      expr.source.discr_stage)
        target_discr = self.places.get_discretization(expr.target.geometry,
                                                      expr.target.discr_stage)

        if source_discr is not target_discr:
            raise NotImplementedError

        rec_density = self._blk_mapper.rec(expr.density)
        if is_zero(rec_density):
            return 0

        if not np.isscalar(rec_density):
            raise NotImplementedError

        actx = self.array_context
        kernel = expr.kernel
        kernel_args = _get_layer_potential_args(self._mat_mapper, expr)

        from sumpy.expansion.local import LineTaylorLocalExpansion
        local_expn = LineTaylorLocalExpansion(kernel, lpot_source.qbx_order)

        from sumpy.qbx import LayerPotentialMatrixBlockGenerator
        mat_gen = LayerPotentialMatrixBlockGenerator(actx.context,
                                                     (local_expn, ))

        assert abs(expr.qbx_forced_limit) > 0
        from pytential import bind, sym
        radii = bind(
            self.places,
            sym.expansion_radii(source_discr.ambient_dim,
                                dofdesc=expr.target))(actx)
        centers = bind(
            self.places,
            sym.expansion_centers(source_discr.ambient_dim,
                                  expr.qbx_forced_limit,
                                  dofdesc=expr.target))(actx)

        from meshmode.dof_array import flatten, thaw
        _, (mat, ) = mat_gen(actx.queue,
                             targets=flatten(thaw(actx, target_discr.nodes())),
                             sources=flatten(thaw(actx, source_discr.nodes())),
                             centers=flatten(centers),
                             expansion_radii=flatten(radii),
                             index_set=self.index_set,
                             **kernel_args)

        waa = bind(
            self.places,
            sym.weights_and_area_elements(source_discr.ambient_dim,
                                          dofdesc=expr.source))(actx)
        waa = flatten(waa)

        mat *= waa[self.index_set.linear_col_indices]
        return rec_density * actx.to_numpy(mat)
Esempio n. 9
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def test_cost_model_order_varying_by_level(ctx_factory):
    """For FMM order varying by level, this checks to ensure that the costs are
    different. The varying-level case should have larger cost.
    """

    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)
    actx = PyOpenCLArrayContext(queue)

    # {{{ constant level to order

    def level_to_order_constant(kernel, kernel_args, tree, level):
        return 1

    lpot_source = get_lpot_source(actx, 2).copy(
            cost_model=QBXCostModel(),
            fmm_level_to_order=level_to_order_constant)
    places = GeometryCollection(lpot_source)

    density_discr = places.get_discretization(places.auto_source.geometry)
    sigma_sym = sym.var("sigma")

    k_sym = LaplaceKernel(2)
    sym_op = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)

    sigma = get_density(actx, density_discr)

    cost_constant, metadata = bind(places, sym_op).cost_per_stage(
            "constant_one", sigma=sigma)

    cost_constant = one(cost_constant.values())
    metadata = one(metadata.values())

    # }}}

    # {{{ varying level to order

    def level_to_order_varying(kernel, kernel_args, tree, level):
        return metadata["nlevels"] - level

    lpot_source = get_lpot_source(actx, 2).copy(
            cost_model=QBXCostModel(),
            fmm_level_to_order=level_to_order_varying)
    places = GeometryCollection(lpot_source)

    density_discr = places.get_discretization(places.auto_source.geometry)

    sigma = get_density(actx, density_discr)

    cost_varying, _ = bind(lpot_source, sym_op).cost_per_stage(
        "constant_one", sigma=sigma)

    cost_varying = one(cost_varying.values())

    # }}}

    assert sum(cost_varying.values()) > sum(cost_constant.values())
Esempio n. 10
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def get_centers_on_side(lpot_src, sign):
    adim = lpot_src.density_discr.ambient_dim
    dim = lpot_src.density_discr.dim

    from pytential import sym, bind
    with cl.CommandQueue(lpot_src.cl_context) as queue:
        nodes = bind(lpot_src.density_discr, sym.nodes(adim))(queue)
        normals = bind(lpot_src.density_discr, sym.normal(adim, dim=dim))(queue)
        expansion_radii = lpot_src._expansion_radii("nsources").with_queue(queue)
        return (nodes + normals * sign * expansion_radii).as_vector(np.object)
Esempio n. 11
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    def map_int_g(self, expr):
        lpot_source = self.places.get_geometry(expr.source.geometry)
        source_discr = self.places.get_discretization(expr.source.geometry,
                                                      expr.source.discr_stage)
        target_discr = self.places.get_discretization(expr.target.geometry,
                                                      expr.target.discr_stage)

        rec_density = self.rec(expr.density)
        if is_zero(rec_density):
            return 0

        assert isinstance(rec_density, np.ndarray)
        if not self.is_kind_matrix(rec_density):
            raise NotImplementedError("layer potentials on non-variables")

        actx = self.array_context
        kernel = expr.kernel
        kernel_args = _get_layer_potential_args(self, expr)

        from sumpy.expansion.local import LineTaylorLocalExpansion
        local_expn = LineTaylorLocalExpansion(kernel, lpot_source.qbx_order)

        from sumpy.qbx import LayerPotentialMatrixGenerator
        mat_gen = LayerPotentialMatrixGenerator(actx.context, (local_expn, ))

        assert abs(expr.qbx_forced_limit) > 0
        from pytential import bind, sym
        radii = bind(
            self.places,
            sym.expansion_radii(source_discr.ambient_dim,
                                dofdesc=expr.target))(actx)
        centers = bind(
            self.places,
            sym.expansion_centers(source_discr.ambient_dim,
                                  expr.qbx_forced_limit,
                                  dofdesc=expr.target))(actx)

        from meshmode.dof_array import flatten, thaw
        _, (mat, ) = mat_gen(actx.queue,
                             targets=flatten(thaw(actx, target_discr.nodes())),
                             sources=flatten(thaw(actx, source_discr.nodes())),
                             centers=flatten(centers),
                             expansion_radii=flatten(radii),
                             **kernel_args)
        mat = actx.to_numpy(mat)

        waa = bind(
            self.places,
            sym.weights_and_area_elements(source_discr.ambient_dim,
                                          dofdesc=expr.source))(actx)
        mat[:, :] *= actx.to_numpy(flatten(waa))
        mat = mat.dot(rec_density)

        return mat
Esempio n. 12
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    def targets_from_sources(sign, dist, dim=2):
        nodes = actx.to_numpy(
            flatten(
                bind(places, sym.nodes(dim, dofdesc=dd))(actx).as_vector(),
                actx)).reshape(dim, -1)
        normals = actx.to_numpy(
            flatten(
                bind(places, sym.normal(dim, dofdesc=dd))(actx).as_vector(),
                actx)).reshape(dim, -1)

        return actx.from_numpy(nodes + normals * sign * dist)
Esempio n. 13
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def test_3d_orientation(ctx_factory, what, mesh_gen_func, visualize=False):
    pytest.importorskip("pytential")

    logging.basicConfig(level=logging.INFO)

    ctx = ctx_factory()
    queue = cl.CommandQueue(ctx)

    mesh = mesh_gen_func()

    logger.info("%d elements" % mesh.nelements)

    from meshmode.discretization import Discretization
    discr = Discretization(ctx, mesh,
            PolynomialWarpAndBlendGroupFactory(1))

    from pytential import bind, sym

    # {{{ check normals point outward

    if what == "torus":
        nodes = sym.nodes(mesh.ambient_dim).as_vector()
        angle = sym.atan2(nodes[1], nodes[0])
        center_nodes = sym.make_obj_array([
                5*sym.cos(angle),
                5*sym.sin(angle),
                0*angle])
        normal_outward_expr = (
                sym.normal(mesh.ambient_dim) | (nodes-center_nodes))

    else:
        normal_outward_expr = (
                sym.normal(mesh.ambient_dim) | sym.nodes(mesh.ambient_dim))

    normal_outward_check = bind(discr, normal_outward_expr)(queue).as_scalar() > 0

    assert normal_outward_check.get().all(), normal_outward_check.get()

    # }}}

    normals = bind(discr, sym.normal(mesh.ambient_dim).xproject(1))(queue)

    if visualize:
        from meshmode.discretization.visualization import make_visualizer
        vis = make_visualizer(queue, discr, 1)

        vis.write_vtk_file("normals.vtu", [
            ("normals", normals),
            ])
Esempio n. 14
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    def weights_and_area_elements(self):
        import pytential.symbolic.primitives as p
        from pytential.symbolic.execution import bind
        with cl.CommandQueue(self.cl_context) as queue:
            # fine_density_discr is not guaranteed to be usable for
            # interpolation/differentiation. Use density_discr to find
            # area element instead, then upsample that.

            area_element = self.resampler(queue,
                    bind(self.density_discr,
                        p.area_element())(queue))

            qweight = bind(self.fine_density_discr, p.QWeight())(queue)

            return (area_element.with_queue(queue)*qweight).with_queue(None)
Esempio n. 15
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def get_arclength_parametrization_derivative(queue, density_discr, where=None):
    """Return x'(s), y'(s). s Follows the same direction as the parametrization.
    (Remark: t is the reference-to-global parametrization of the discretization).
    """
    queue = setup_command_queue(queue=queue)
    dim = 2

    # xp = dx/dt, yp = dy/dt, sp = ds/dt
    xp, yp = sym.parametrization_derivative_matrix(dim, dim - 1, where)
    sp = (xp[0]**2 + yp[0]**2)**(1 / 2)

    xps = xp[0] / sp
    yps = yp[0] / sp

    return bind(density_discr, xps)(queue), bind(density_discr, yps)(queue)
Esempio n. 16
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def get_bound_op(places):
    from sumpy.kernel import LaplaceKernel
    op = sym.S(LaplaceKernel(places.ambient_dim),
               sym.var("sigma"),
               qbx_forced_limit=+1)

    return bind(places, op)
Esempio n. 17
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    def weights_and_area_elements(self):
        from pytential import bind, sym
        with cl.CommandQueue(self.cl_context) as queue:
            waa = bind(self,
                       sym.weights_and_area_elements(self.ambient_dim))(queue)

            return waa.with_queue(None)
Esempio n. 18
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def _get_layer_potential_args(actx,
                              places,
                              expr,
                              context=None,
                              include_args=None):
    """
    :arg expr: symbolic layer potential expression containing the kernel arguments.
    :arg include_args: subset of the kernel arguments to evaluate.
    """

    from pytential import bind
    if context is None:
        context = {}

    if include_args is not None:
        kernel_arguments = {
            k: v
            for k, v in expr.kernel_arguments.items() if k in include_args
        }
    else:
        kernel_arguments = expr.kernel_arguments

    from pytential.source import evaluate_kernel_arguments
    return evaluate_kernel_arguments(actx,
                                     lambda expr: bind(places, expr)
                                     (actx, **context),
                                     kernel_arguments,
                                     flat=True)
Esempio n. 19
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def get_lpot_cost(queue, geometry_getter, kind):
    lpot_source = geometry_getter(queue)

    from pytential import sym, bind
    sigma_sym = sym.var("sigma")
    from sumpy.kernel import LaplaceKernel
    k_sym = LaplaceKernel(lpot_source.ambient_dim)
    op = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)

    bound_op = bind(lpot_source, op)

    density_discr = lpot_source.density_discr
    nodes = density_discr.nodes().with_queue(queue)
    sigma = cl.clmath.sin(10 * nodes[0])

    from pytools import one
    if kind == "actual":
        timing_data = {}
        result = bound_op.eval(queue, {"sigma": sigma},
                               timing_data=timing_data)
        assert not np.isnan(result.get(queue)).any()
        result = one(timing_data.values())

    elif kind == "model":
        perf_results = bound_op.get_modeled_performance(queue, sigma=sigma)
        result = one(perf_results.values())

    return result
Esempio n. 20
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def test_timing_data_gathering(ctx_factory):
    """Test that timing data gathering can execute succesfully."""

    pytest.importorskip("pyfmmlib")

    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx,
            properties=cl.command_queue_properties.PROFILING_ENABLE)
    actx = PyOpenCLArrayContext(queue)

    lpot_source = get_lpot_source(actx, 2)
    places = GeometryCollection(lpot_source)

    dofdesc = places.auto_source.to_stage1()
    density_discr = places.get_discretization(dofdesc.geometry)
    sigma = get_density(actx, density_discr)

    sigma_sym = sym.var("sigma")
    k_sym = LaplaceKernel(lpot_source.ambient_dim)
    sym_op_S = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)

    op_S = bind(places, sym_op_S)

    timing_data = {}
    op_S.eval(dict(sigma=sigma), timing_data=timing_data, array_context=actx)
    assert timing_data
    print(timing_data)
Esempio n. 21
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 def eval_inc_field_at(tgt):
     if 0:
         # plane wave
         return bind(
                 tgt,
                 get_sym_maxwell_plane_wave(
                     amplitude_vec=np.array([1, 1, 1]),
                     v=np.array([1, 0, 0]),
                     omega=case.k)
                 )(queue)
     else:
         # point source
         return bind(
                 (test_source, tgt),
                 get_sym_maxwell_point_source(mfie.kernel, j_sym, mfie.k)
                 )(queue, j=src_j, k=case.k)
Esempio n. 22
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def test_geometry(ctx_getter):
    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    nelements = 30
    order = 5

    mesh = make_curve_mesh(partial(ellipse, 1),
            np.linspace(0, 1, nelements+1),
            order)

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    discr = Discretization(cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(order))

    import pytential.symbolic.primitives as prim
    area_sym = prim.integral(2, 1, 1)

    area = bind(discr, area_sym)(queue)

    err = abs(area-2*np.pi)
    print(err)
    assert err < 1e-3
Esempio n. 23
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def get_interleaved_centers(queue, lpot_source):
    """
    Return an array of shape (dim, ncenters) in which interior centers are placed
    next to corresponding exterior centers.
    """
    from pytential import bind, sym
    int_centers = bind(lpot_source,
                       sym.expansion_centers(lpot_source.ambient_dim,
                                             -1))(queue)
    ext_centers = bind(lpot_source,
                       sym.expansion_centers(lpot_source.ambient_dim,
                                             +1))(queue)

    from pytential.symbolic.dof_connection import CenterGranularityConnection
    interleaver = CenterGranularityConnection(lpot_source.density_discr)
    return interleaver(queue, [int_centers, ext_centers])
Esempio n. 24
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    def check_expansion_disks_undisturbed_by_sources(self,
            stage1_density_discr, tree, peer_lists,
            expansion_disturbance_tolerance,
            refine_flags,
            debug, wait_for=None):

        # Avoid generating too many kernels.
        from pytools import div_ceil
        max_levels = MAX_LEVELS_INCREMENT * div_ceil(
                tree.nlevels, MAX_LEVELS_INCREMENT)

        knl = self.code_container.expansion_disk_undisturbed_by_sources_checker(
                tree.dimensions,
                tree.coord_dtype, tree.box_id_dtype,
                peer_lists.peer_list_starts.dtype,
                tree.particle_id_dtype,
                max_levels)

        if debug:
            npanels_to_refine_prev = cl.array.sum(refine_flags).get()

        found_panel_to_refine = cl.array.zeros(self.queue, 1, np.int32)
        found_panel_to_refine.finish()
        unwrap_args = AreaQueryElementwiseTemplate.unwrap_args

        from pytential import bind, sym
        center_danger_zone_radii = flatten(
            bind(stage1_density_discr,
                sym.expansion_radii(stage1_density_discr.ambient_dim,
                    granularity=sym.GRANULARITY_CENTER))(self.array_context))

        evt = knl(
            *unwrap_args(
                tree, peer_lists,
                tree.box_to_qbx_source_starts,
                tree.box_to_qbx_source_lists,
                tree.qbx_panel_to_source_starts,
                tree.qbx_panel_to_center_starts,
                tree.qbx_user_source_slice.start,
                tree.qbx_user_center_slice.start,
                tree.sorted_target_ids,
                center_danger_zone_radii,
                expansion_disturbance_tolerance,
                tree.nqbxpanels,
                refine_flags,
                found_panel_to_refine,
                *tree.sources),
            range=slice(tree.nqbxcenters),
            queue=self.queue,
            wait_for=wait_for)

        cl.wait_for_events([evt])

        if debug:
            npanels_to_refine = cl.array.sum(refine_flags).get()
            if npanels_to_refine > npanels_to_refine_prev:
                logger.debug("refiner: found {} panel(s) to refine".format(
                    npanels_to_refine - npanels_to_refine_prev))

        return found_panel_to_refine.get()[0] == 1
Esempio n. 25
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def test_geometry(ctx_factory):
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)
    actx = PyOpenCLArrayContext(queue)

    nelements = 30
    order = 5

    mesh = make_curve_mesh(partial(ellipse, 1),
            np.linspace(0, 1, nelements+1),
            order)

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    discr = Discretization(actx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(order))

    import pytential.symbolic.primitives as prim
    area_sym = prim.integral(2, 1, 1)

    area = bind(discr, area_sym)(actx)

    err = abs(area-2*np.pi)
    print(err)
    assert err < 1e-3
Esempio n. 26
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def get_bound_op(lpot_source):
    from sumpy.kernel import LaplaceKernel
    sigma_sym = sym.var("sigma")
    k_sym = LaplaceKernel(lpot_source.ambient_dim)
    op = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)

    return bind(lpot_source, op)
Esempio n. 27
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def get_slp_wall_times(lpot_source, fmm_order, qbx_order):
    queue = cl.CommandQueue(lpot_source.cl_context)

    lpot_source = lpot_source.copy(
        qbx_order=qbx_order,
        fmm_level_to_order=(False if fmm_order is False else
                            lambda *args: fmm_order))

    d = lpot_source.ambient_dim

    u_sym = sym.var("u")

    from sumpy.kernel import LaplaceKernel
    S = sym.S(LaplaceKernel(d), u_sym, qbx_forced_limit=-1)
    density_discr = lpot_source.density_discr

    u = cl.array.empty(queue, density_discr.nnodes, np.float64)
    u.fill(1)

    op = bind(lpot_source, S)

    # Warmup
    op(queue, u=u)

    times = []
    from time import perf_counter as curr_time

    for _ in range(WALL_TIME_EXPERIMENT_TIMING_ROUNDS):
        t_start = curr_time()
        op(queue, u=u)
        t_end = curr_time()
        times.append(t_end - t_start)

    return times
Esempio n. 28
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    def map_num_reference_derivative(self, expr):
        from pytential import bind, sym
        rec_operand = self.rec(expr.operand)

        assert isinstance(rec_operand, np.ndarray)
        if self.is_kind_matrix(rec_operand):
            raise NotImplementedError("derivatives")

        actx = self.array_context
        dofdesc = expr.dofdesc
        op = sym.NumReferenceDerivative(ref_axes=expr.ref_axes,
                                        operand=sym.var("u"),
                                        dofdesc=dofdesc)

        discr = self.places.get_discretization(dofdesc.geometry,
                                               dofdesc.discr_stage)

        template_ary = thaw(discr.nodes()[0], actx)
        rec_operand = unflatten(template_ary, actx.from_numpy(rec_operand),
                                actx)

        return actx.to_numpy(
            flatten(
                bind(self.places, op)(self.array_context, u=rec_operand),
                actx))
Esempio n. 29
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def test_mean_curvature(ctx_factory,
                        discr_name,
                        resolutions,
                        discr_and_ref_mean_curvature_getter,
                        visualize=False):
    ctx = ctx_factory()
    queue = cl.CommandQueue(ctx)
    actx = PyOpenCLArrayContext(queue)

    from pytools.convergence import EOCRecorder
    eoc = EOCRecorder()

    for r in resolutions:
        discr, ref_mean_curvature = \
                discr_and_ref_mean_curvature_getter(actx, r)
        mean_curvature = bind(discr,
                              sym.mean_curvature(discr.ambient_dim))(actx)

        h = 1.0 / r
        from meshmode.dof_array import flat_norm
        h_error = flat_norm(mean_curvature - ref_mean_curvature, np.inf)
        eoc.add_data_point(h, h_error)
    print(eoc)

    order = min([g.order for g in discr.groups])
    assert eoc.order_estimate() > order - 1.1
Esempio n. 30
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    def map_node_coordinate_component(self, expr):
        from pytential import bind, sym
        op = sym.NodeCoordinateComponent(expr.ambient_axis,
                                         dofdesc=expr.dofdesc)

        actx = self.array_context
        return actx.to_numpy(flatten(bind(self.places, op)(actx), actx))
Esempio n. 31
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def test_interpolation(actx_factory, name, source_discr_stage, target_granularity):
    actx = actx_factory()

    nelements = 32
    target_order = 7
    qbx_order = 4

    where = sym.as_dofdesc("test_interpolation")
    from_dd = sym.DOFDescriptor(
            geometry=where.geometry,
            discr_stage=source_discr_stage,
            granularity=sym.GRANULARITY_NODE)
    to_dd = sym.DOFDescriptor(
            geometry=where.geometry,
            discr_stage=sym.QBX_SOURCE_QUAD_STAGE2,
            granularity=target_granularity)

    mesh = mgen.make_curve_mesh(mgen.starfish,
            np.linspace(0.0, 1.0, nelements + 1),
            target_order)
    discr = Discretization(actx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(target_order))

    from pytential.qbx import QBXLayerPotentialSource
    qbx = QBXLayerPotentialSource(discr,
            fine_order=4 * target_order,
            qbx_order=qbx_order,
            fmm_order=False)

    from pytential import GeometryCollection
    places = GeometryCollection(qbx, auto_where=where)

    sigma_sym = sym.var("sigma")
    op_sym = sym.sin(sym.interp(from_dd, to_dd, sigma_sym))
    bound_op = bind(places, op_sym, auto_where=where)

    def discr_and_nodes(stage):
        density_discr = places.get_discretization(where.geometry, stage)
        return density_discr, actx.to_numpy(
                flatten(density_discr.nodes(), actx)
                ).reshape(density_discr.ambient_dim, -1)

    _, target_nodes = discr_and_nodes(sym.QBX_SOURCE_QUAD_STAGE2)
    source_discr, source_nodes = discr_and_nodes(source_discr_stage)

    sigma_target = np.sin(la.norm(target_nodes, axis=0))
    sigma_dev = unflatten(
            thaw(source_discr.nodes()[0], actx),
            actx.from_numpy(la.norm(source_nodes, axis=0)), actx)
    sigma_target_interp = actx.to_numpy(
            flatten(bound_op(actx, sigma=sigma_dev), actx)
            )

    if name in ("default", "default_explicit", "stage2", "quad"):
        error = la.norm(sigma_target_interp - sigma_target) / la.norm(sigma_target)
        assert error < 1.0e-10
    elif name in ("stage2_center",):
        assert len(sigma_target_interp) == 2 * len(sigma_target)
    else:
        raise ValueError(f"unknown test case name: {name}")
Esempio n. 32
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def test_off_surface_eval(ctx_factory, use_fmm, do_plot=False):
    logging.basicConfig(level=logging.INFO)

    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    nelements = 30
    target_order = 8
    qbx_order = 3
    if use_fmm:
        fmm_order = qbx_order
    else:
        fmm_order = False

    mesh = make_curve_mesh(partial(ellipse, 3),
                           np.linspace(0, 1, nelements + 1), target_order)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    pre_density_discr = Discretization(
        cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    qbx, _ = QBXLayerPotentialSource(
        pre_density_discr,
        4 * target_order,
        qbx_order,
        fmm_order=fmm_order,
    ).with_refinement()

    density_discr = qbx.density_discr

    from sumpy.kernel import LaplaceKernel
    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=-2)

    sigma = density_discr.zeros(queue) + 1

    fplot = FieldPlotter(np.zeros(2), extent=0.54, npoints=30)
    from pytential.target import PointsTarget
    fld_in_vol = bind((qbx, PointsTarget(fplot.points)), op)(queue,
                                                             sigma=sigma)

    err = cl.clmath.fabs(fld_in_vol - (-1))

    linf_err = cl.array.max(err).get()
    print("l_inf error:", linf_err)

    if do_plot:
        fplot.show_scalar_in_matplotlib(fld_in_vol.get())
        import matplotlib.pyplot as pt
        pt.colorbar()
        pt.show()

    assert linf_err < 1e-3
Esempio n. 33
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def test_off_surface_eval(actx_factory, use_fmm, visualize=False):
    logging.basicConfig(level=logging.INFO)

    actx = actx_factory()

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    nelements = 30
    target_order = 8
    qbx_order = 3
    if use_fmm:
        fmm_order = qbx_order
    else:
        fmm_order = False

    mesh = mgen.make_curve_mesh(partial(mgen.ellipse, 3),
                                np.linspace(0, 1, nelements + 1), target_order)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    pre_density_discr = Discretization(
        actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    qbx = QBXLayerPotentialSource(
        pre_density_discr,
        4 * target_order,
        qbx_order,
        fmm_order=fmm_order,
    )

    from pytential.target import PointsTarget
    fplot = FieldPlotter(np.zeros(2), extent=0.54, npoints=30)
    targets = PointsTarget(actx.freeze(actx.from_numpy(fplot.points)))

    places = GeometryCollection((qbx, targets))
    density_discr = places.get_discretization(places.auto_source.geometry)

    from sumpy.kernel import LaplaceKernel
    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=-2)

    sigma = density_discr.zeros(actx) + 1
    fld_in_vol = bind(places, op)(actx, sigma=sigma)
    fld_in_vol_exact = -1

    linf_err = actx.to_numpy(
        actx.np.linalg.norm(fld_in_vol - fld_in_vol_exact, ord=np.inf))
    logger.info("l_inf error: %.12e", linf_err)

    if visualize:
        fplot.show_scalar_in_matplotlib(actx.to_numpy(fld_in_vol))
        import matplotlib.pyplot as pt
        pt.colorbar()
        pt.show()

    assert linf_err < 1e-3
Esempio n. 34
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        def eval_repr_at(tgt, source=None):
            if source is None:
                source = qbx

            return bind((source, tgt), sym_repr)(queue,
                                                 jt=jt,
                                                 rho=rho,
                                                 **knl_kwargs)
Esempio n. 35
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 def weights_and_area_elements(self):
     from pytential import bind, sym
     with cl.CommandQueue(self.cl_context) as queue:
         return bind(
             self,
             sym.weights_and_area_elements(
                 self.ambient_dim, dofdesc=sym.QBX_SOURCE_QUAD_STAGE2))(
                     queue).with_queue(None)
def main():
    cl_ctx = cl.create_some_context()
    queue = cl.CommandQueue(cl_ctx)

    target_order = 10

    from functools import partial
    nelements = 30
    qbx_order = 4

    from sumpy.kernel import LaplaceKernel
    from meshmode.mesh.generation import (  # noqa
            ellipse, cloverleaf, starfish, drop, n_gon, qbx_peanut,
            make_curve_mesh)
    mesh = make_curve_mesh(partial(ellipse, 1),
            np.linspace(0, 1, nelements+1),
            target_order)

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    density_discr = Discretization(cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(target_order))

    from pytential.qbx import QBXLayerPotentialSource
    qbx = QBXLayerPotentialSource(density_discr, 4*target_order,
            qbx_order, fmm_order=False)

    from pytools.obj_array import join_fields
    sig_sym = sym.var("sig")
    knl = LaplaceKernel(2)
    op = join_fields(
            sym.tangential_derivative(mesh.ambient_dim,
                sym.D(knl, sig_sym, qbx_forced_limit=+1)).as_scalar(),
            sym.tangential_derivative(mesh.ambient_dim,
                sym.D(knl, sig_sym, qbx_forced_limit=-1)).as_scalar(),
            )

    nodes = density_discr.nodes().with_queue(queue)
    angle = cl.clmath.atan2(nodes[1], nodes[0])
    n = 10
    sig = cl.clmath.sin(n*angle)
    dt_sig = n*cl.clmath.cos(n*angle)

    res = bind(qbx, op)(queue, sig=sig)

    extval = res[0].get()
    intval = res[1].get()
    pv = 0.5*(extval + intval)

    dt_sig_h = dt_sig.get()

    import matplotlib.pyplot as pt
    pt.plot(extval, label="+num")
    pt.plot(pv + dt_sig_h*0.5, label="+ex")
    pt.legend(loc="best")
    pt.show()
Esempio n. 37
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def test_unregularized_off_surface_fmm_vs_direct(ctx_getter):
    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    nelements = 300
    target_order = 8
    fmm_order = 4

    mesh = make_curve_mesh(WobblyCircle.random(8, seed=30),
                np.linspace(0, 1, nelements+1),
                target_order)

    from pytential.unregularized import UnregularizedLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    direct = UnregularizedLayerPotentialSource(
            density_discr,
            fmm_order=False,
            )
    fmm = direct.copy(
            fmm_level_to_order=lambda kernel, kernel_args, tree, level: fmm_order)

    sigma = density_discr.zeros(queue) + 1

    fplot = FieldPlotter(np.zeros(2), extent=5, npoints=100)
    from pytential.target import PointsTarget
    ptarget = PointsTarget(fplot.points)
    from sumpy.kernel import LaplaceKernel

    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=None)

    direct_fld_in_vol = bind((direct, ptarget), op)(queue, sigma=sigma)
    fmm_fld_in_vol = bind((fmm, ptarget), op)(queue, sigma=sigma)

    err = cl.clmath.fabs(fmm_fld_in_vol - direct_fld_in_vol)

    linf_err = cl.array.max(err).get()
    print("l_inf error:", linf_err)
    assert linf_err < 5e-3
Esempio n. 38
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def test_unregularized_with_ones_kernel(ctx_getter):
    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    nelements = 10
    order = 8

    mesh = make_curve_mesh(partial(ellipse, 1),
            np.linspace(0, 1, nelements+1),
            order)

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    discr = Discretization(cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(order))

    from pytential.unregularized import UnregularizedLayerPotentialSource
    lpot_src = UnregularizedLayerPotentialSource(discr)

    from sumpy.kernel import one_kernel_2d

    expr = sym.IntG(one_kernel_2d, sym.var("sigma"), qbx_forced_limit=None)

    from pytential.target import PointsTarget
    op_self = bind(lpot_src, expr)
    op_nonself = bind((lpot_src, PointsTarget(np.zeros((2, 1), dtype=float))), expr)

    with cl.CommandQueue(cl_ctx) as queue:
        sigma = cl.array.zeros(queue, discr.nnodes, dtype=float)
        sigma.fill(1)
        sigma.finish()

        result_self = op_self(queue, sigma=sigma)
        result_nonself = op_nonself(queue, sigma=sigma)

    assert np.allclose(result_self.get(), 2 * np.pi)
    assert np.allclose(result_nonself.get(), 2 * np.pi)
Esempio n. 39
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def test_mean_curvature(ctx_factory, discr_name,
        discr_and_ref_mean_curvature_getter):
    if discr_name == "unit sphere":
        pytest.skip("not implemented in 3D yet")

    import pytential.symbolic.primitives as prim
    ctx = ctx_factory()

    discr, ref_mean_curvature = discr_and_ref_mean_curvature_getter(ctx)

    with cl.CommandQueue(ctx) as queue:
        from pytential import bind
        mean_curvature = bind(
            discr,
            prim.mean_curvature(discr.ambient_dim))(queue)

    assert np.allclose(mean_curvature.get(), ref_mean_curvature)
Esempio n. 40
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    def visualize_refinement(niter, stage_nr, stage_name, flags):
        if not visualize:
            return

        if stage_nr == 1:
            discr = lpot_source.density_discr
        elif stage_nr == 2:
            discr = lpot_source.stage2_density_discr
        else:
            raise ValueError("unexpected stage number")

        flags = flags.get()
        logger.info("for stage %s: splitting %d/%d stage-%d elements",
                stage_name, np.sum(flags), discr.mesh.nelements, stage_nr)

        from meshmode.discretization.visualization import make_visualizer
        vis = make_visualizer(wrangler.queue, discr, 3)

        assert len(flags) == discr.mesh.nelements

        flags = flags.astype(np.bool)
        nodes_flags = np.zeros(discr.nnodes)
        for grp in discr.groups:
            meg = grp.mesh_el_group
            grp.view(nodes_flags)[
                    flags[meg.element_nr_base:meg.nelements+meg.element_nr_base]] = 1

        nodes_flags = cl.array.to_device(wrangler.queue, nodes_flags)
        vis_data = [
            ("refine_flags", nodes_flags),
            ]

        if 0:
            from pytential import sym, bind
            bdry_normals = bind(discr, sym.normal(discr.ambient_dim))(
                    wrangler.queue).as_vector(dtype=object)
            vis_data.append(("bdry_normals", bdry_normals),)

        vis.write_vtk_file("refinement-%s-%03d.vtu" % (stage_name, niter), vis_data)
Esempio n. 41
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def test_identities(ctx_getter, zero_op_name, curve_name, curve_f, qbx_order, k):
    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    target_order = 7

    u_sym = sym.var("u")
    grad_u_sym = sym.VectorVariable("grad_u")
    dn_u_sym = sym.var("dn_u")

    if k == 0:
        k_sym = 0
    else:
        k_sym = "k"

    zero_op_table = {
            "green":
            sym.S(k_sym, dn_u_sym) - sym.D(k_sym, u_sym) - 0.5*u_sym,

            "green_grad":
            d1.nabla * d1(sym.S(k_sym, dn_u_sym))
            - d2.nabla * d2(sym.D(k_sym, u_sym))
            - 0.5*grad_u_sym,

            # only for k==0:
            "zero_calderon":
            -sym.Dp(0, sym.S(0, u_sym))
            - 0.25*u_sym + sym.Sp(0, sym.Sp(0, u_sym))
            }
    order_table = {
            "green": qbx_order,
            "green_grad": qbx_order-1,
            "zero_calderon": qbx_order-1,
            }

    zero_op = zero_op_table[zero_op_name]

    from pytools.convergence import EOCRecorder
    eoc_rec = EOCRecorder()

    for nelements in [30, 50, 70]:
        mesh = make_curve_mesh(curve_f,
                np.linspace(0, 1, nelements+1),
                target_order)

        from meshmode.discretization import Discretization
        from meshmode.discretization.poly_element import \
                InterpolatoryQuadratureSimplexGroupFactory
        from pytential.qbx import QBXLayerPotentialSource
        density_discr = Discretization(
                cl_ctx, mesh,
                InterpolatoryQuadratureSimplexGroupFactory(target_order))

        qbx = QBXLayerPotentialSource(density_discr, 4*target_order,
                qbx_order,
                # Don't use FMM for now
                fmm_order=False)

        # {{{ compute values of a solution to the PDE

        nodes_host = density_discr.nodes().get(queue)
        normal = bind(density_discr, sym.normal())(queue).as_vector(np.object)
        normal_host = [normal[0].get(), normal[1].get()]

        if k != 0:
            angle = 0.3
            wave_vec = np.array([np.cos(angle), np.sin(angle)])
            u = np.exp(1j*k*np.tensordot(wave_vec, nodes_host, axes=1))
            grad_u = 1j*k*wave_vec[:, np.newaxis]*u
        else:
            center = np.array([3, 1])
            diff = nodes_host - center[:, np.newaxis]
            dist_squared = np.sum(diff**2, axis=0)
            dist = np.sqrt(dist_squared)
            u = np.log(dist)
            grad_u = diff/dist_squared

        dn_u = normal_host[0]*grad_u[0] + normal_host[1]*grad_u[1]

        # }}}

        u_dev = cl.array.to_device(queue, u)
        dn_u_dev = cl.array.to_device(queue, dn_u)
        grad_u_dev = cl.array.to_device(queue, grad_u)

        key = (qbx_order, curve_name, nelements, zero_op_name)

        bound_op = bind(qbx, zero_op)
        error = bound_op(
                queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=k)
        if 0:
            pt.plot(error)
            pt.show()

        l2_error_norm = norm(density_discr, queue, error)
        print(key, l2_error_norm)

        eoc_rec.add_data_point(1/nelements, l2_error_norm)

    print(eoc_rec)
    tgt_order = order_table[zero_op_name]
    assert eoc_rec.order_estimate() > tgt_order - 1.3
Esempio n. 42
0
def main():
    import logging
    logging.basicConfig(level=logging.INFO)

    ctx = cl.create_some_context()
    queue = cl.CommandQueue(ctx)

    mesh = generate_gmsh(
            FileSource("circle.step"), 2, order=mesh_order,
            force_ambient_dim=2,
            other_options=["-string", "Mesh.CharacteristicLengthMax = %g;" % h]
            )

    logger.info("%d elements" % mesh.nelements)

    # {{{ discretizations and connections

    vol_discr = Discretization(ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(vol_quad_order))
    ovsmp_vol_discr = Discretization(ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(vol_ovsmp_quad_order))

    from meshmode.discretization.connection import (
            make_boundary_restriction, make_same_mesh_connection)
    bdry_mesh, bdry_discr, bdry_connection = make_boundary_restriction(
            queue, vol_discr,
            InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))

    vol_to_ovsmp_vol = make_same_mesh_connection(
            queue, ovsmp_vol_discr, vol_discr)

    # }}}

    # {{{ visualizers

    vol_vis = make_visualizer(queue, vol_discr, 20)
    bdry_vis = make_visualizer(queue, bdry_discr, 20)

    # }}}

    vol_x = vol_discr.nodes().with_queue(queue)
    ovsmp_vol_x = ovsmp_vol_discr.nodes().with_queue(queue)

    rhs = rhs_func(vol_x[0], vol_x[1])
    poisson_true_sol = sol_func(vol_x[0], vol_x[1])

    vol_vis.write_vtk_file("volume.vtu", [("f", rhs)])

    bdry_normals = bind(bdry_discr, p.normal())(queue).as_vector(dtype=object)
    bdry_vis.write_vtk_file("boundary.vtu", [
        ("normals", bdry_normals)
        ])

    bdry_nodes = bdry_discr.nodes().with_queue(queue)
    bdry_f = rhs_func(bdry_nodes[0], bdry_nodes[1])
    bdry_f_2 = bdry_connection(queue, rhs)

    bdry_vis.write_vtk_file("y.vtu", [("f", bdry_f_2)])

    if 0:
        vol_vis.show_scalar_in_mayavi(rhs, do_show=False)
        bdry_vis.show_scalar_in_mayavi(bdry_f - bdry_f_2, line_width=10,
                do_show=False)

        import mayavi.mlab as mlab
        mlab.colorbar()
        mlab.show()

    # {{{ compute volume potential

    from sumpy.qbx import LayerPotential
    from sumpy.expansion.local import LineTaylorLocalExpansion

    def get_kernel():
        from sumpy.symbolic import pymbolic_real_norm_2
        from pymbolic.primitives import (make_sym_vector, Variable as var)

        r = pymbolic_real_norm_2(make_sym_vector("d", 3))
        expr = var("log")(r)
        scaling = 1/(2*var("pi"))

        from sumpy.kernel import ExpressionKernel
        return ExpressionKernel(
                dim=3,
                expression=expr,
                scaling=scaling,
                is_complex_valued=False)

    laplace_2d_in_3d_kernel = get_kernel()

    layer_pot = LayerPotential(ctx, [
        LineTaylorLocalExpansion(laplace_2d_in_3d_kernel,
            order=vol_qbx_order)])

    targets = cl.array.zeros(queue, (3,) + vol_x.shape[1:], vol_x.dtype)
    targets[:2] = vol_x

    center_dist = np.min(
            cl.clmath.sqrt(
                bind(vol_discr, p.area_element())(queue)).get())

    centers = make_obj_array([ci.copy().reshape(vol_discr.nnodes) for ci in targets])
    centers[2][:] = center_dist

    sources = cl.array.zeros(queue, (3,) + ovsmp_vol_x.shape[1:], ovsmp_vol_x.dtype)
    sources[:2] = ovsmp_vol_x

    ovsmp_rhs = vol_to_ovsmp_vol(queue, rhs)
    ovsmp_vol_weights = bind(ovsmp_vol_discr, p.area_element() * p.QWeight())(queue)

    evt, (vol_pot,) = layer_pot(
            queue,
            targets=targets.reshape(3, vol_discr.nnodes),
            centers=centers,
            sources=sources.reshape(3, ovsmp_vol_discr.nnodes),
            strengths=(
                (ovsmp_vol_weights*ovsmp_rhs).reshape(ovsmp_vol_discr.nnodes),)
            )

    vol_pot_bdry = bdry_connection(queue, vol_pot)

    # }}}

    # {{{ solve bvp

    from sumpy.kernel import LaplaceKernel
    from pytential.symbolic.pde.scalar import DirichletOperator
    op = DirichletOperator(LaplaceKernel(2), -1, use_l2_weighting=True)

    sym_sigma = sym.var("sigma")
    op_sigma = op.operator(sym_sigma)

    from pytential.qbx import QBXLayerPotentialSource
    qbx = QBXLayerPotentialSource(
            bdry_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
            fmm_order=fmm_order
            )

    bound_op = bind(qbx, op_sigma)

    poisson_bc = poisson_bc_func(bdry_nodes[0], bdry_nodes[1])
    bvp_bc = poisson_bc - vol_pot_bdry
    bdry_f = rhs_func(bdry_nodes[0], bdry_nodes[1])

    bvp_rhs = bind(bdry_discr, op.prepare_rhs(sym.var("bc")))(queue, bc=bvp_bc)

    from pytential.solve import gmres
    gmres_result = gmres(
            bound_op.scipy_op(queue, "sigma"),
            bvp_rhs, tol=1e-14, progress=True,
            hard_failure=False)

    sigma = gmres_result.solution
    print("gmres state:", gmres_result.state)

    # }}}

    bvp_sol = bind(
            (qbx, vol_discr),
            op.representation(sym_sigma))(queue, sigma=sigma)

    poisson_sol = bvp_sol + vol_pot
    poisson_err = poisson_sol-poisson_true_sol

    rel_err = (
            norm(vol_discr, queue, poisson_err)
            /
            norm(vol_discr, queue, poisson_true_sol))
    bdry_vis.write_vtk_file("poisson-boundary.vtu", [
        ("vol_pot_bdry", vol_pot_bdry),
        ("sigma", sigma),
        ])

    vol_vis.write_vtk_file("poisson-volume.vtu", [
        ("bvp_sol", bvp_sol),
        ("poisson_sol", poisson_sol),
        ("poisson_true_sol", poisson_true_sol),
        ("poisson_err", poisson_err),
        ("vol_pot", vol_pot),
        ("rhs", rhs),
        ])

    print("h = %s" % h)
    print("mesh_order = %s" % mesh_order)
    print("vol_quad_order = %s" % vol_quad_order)
    print("vol_ovsmp_quad_order = %s" % vol_ovsmp_quad_order)
    print("bdry_quad_order = %s" % bdry_quad_order)
    print("bdry_ovsmp_quad_order = %s" % bdry_ovsmp_quad_order)
    print("qbx_order = %s" % qbx_order)
    print("vol_qbx_order = %s" % vol_qbx_order)
    print("fmm_order = %s" % fmm_order)
    print()
    print("rel err: %g" % rel_err)
Esempio n. 43
0
def main():
    # cl.array.to_device(queue, numpy_array)
    from meshmode.mesh.io import generate_gmsh, FileSource
    mesh = generate_gmsh(
            FileSource("ellipsoid.step"), 2, order=2,
            other_options=["-string", "Mesh.CharacteristicLengthMax = %g;" % h])

    from meshmode.mesh.processing import perform_flips
    # Flip elements--gmsh generates inside-out geometry.
    mesh = perform_flips(mesh, np.ones(mesh.nelements))

    print("%d elements" % mesh.nelements)

    from meshmode.mesh.processing import find_bounding_box
    bbox_min, bbox_max = find_bounding_box(mesh)
    bbox_center = 0.5*(bbox_min+bbox_max)
    bbox_size = max(bbox_max-bbox_min) / 2

    logger.info("%d elements" % mesh.nelements)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))

    qbx = QBXLayerPotentialSource(density_discr, 4*target_order, qbx_order,
            fmm_order=qbx_order + 10, fmm_backend="fmmlib")

    from pytential.symbolic.pde.maxwell import MuellerAugmentedMFIEOperator
    pde_op = MuellerAugmentedMFIEOperator(
            omega=0.4,
            epss=[1.4, 1.0],
            mus=[1.2, 1.0],
            )
    from pytential import bind, sym

    unk = pde_op.make_unknown("sigma")
    sym_operator = pde_op.operator(unk)
    sym_rhs = pde_op.rhs(
            sym.make_sym_vector("Einc", 3),
            sym.make_sym_vector("Hinc", 3))
    sym_repr = pde_op.representation(0, unk)

    if 1:
        expr = sym_repr
        print(sym.pretty(expr))

        print("#"*80)
        from pytential.target import PointsTarget

        tgt_points=np.zeros((3,1))
        tgt_points[0,0] = 100
        tgt_points[1,0] = -200
        tgt_points[2,0] = 300

        bound_op = bind((qbx, PointsTarget(tgt_points)), expr)
        print(bound_op.code)

    if 1:

        def green3e(x,y,z,source,strength,k):
        # electric field corresponding to dyadic green's function
        # due to monochromatic electric dipole located at "source".
        # "strength" is the the intensity of the dipole.
        #  E = (I + Hess)(exp(ikr)/r) dot (strength)
        #
            dx = x - source[0]
            dy = y - source[1]
            dz = z - source[2]
            rr = np.sqrt(dx**2 + dy**2 + dz**2)

            fout = np.exp(1j*k*rr)/rr
            evec = fout*strength
            qmat = np.zeros((3,3),dtype=np.complex128)

            qmat[0,0]=(2*dx**2-dy**2-dz**2)*(1-1j*k*rr)
            qmat[1,1]=(2*dy**2-dz**2-dx**2)*(1-1j*k*rr)
            qmat[2,2]=(2*dz**2-dx**2-dy**2)*(1-1j*k*rr)

            qmat[0,0]=qmat[0,0]+(-k**2*dx**2*rr**2)
            qmat[1,1]=qmat[1,1]+(-k**2*dy**2*rr**2)
            qmat[2,2]=qmat[2,2]+(-k**2*dz**2*rr**2)

            qmat[0,1]=(3-k**2*rr**2-3*1j*k*rr)*(dx*dy)
            qmat[1,2]=(3-k**2*rr**2-3*1j*k*rr)*(dy*dz)
            qmat[2,0]=(3-k**2*rr**2-3*1j*k*rr)*(dz*dx)

            qmat[1,0]=qmat[0,1]
            qmat[2,1]=qmat[1,2]
            qmat[0,2]=qmat[2,0]

            fout=np.exp(1j*k*rr)/rr**5/k**2

            fvec = fout*np.dot(qmat,strength)
            evec = evec + fvec
            return evec

        def green3m(x,y,z,source,strength,k):
        # magnetic field corresponding to dyadic green's function
        # due to monochromatic electric dipole located at "source".
        # "strength" is the the intensity of the dipole.
        #  H = curl((I + Hess)(exp(ikr)/r) dot (strength)) = 
        #  strength \cross \grad (exp(ikr)/r)
        #
            dx = x - source[0]
            dy = y - source[1]
            dz = z - source[2]
            rr = np.sqrt(dx**2 + dy**2 + dz**2)

            fout=(1-1j*k*rr)*np.exp(1j*k*rr)/rr**3
            fvec = np.zeros(3,dtype=np.complex128)
            fvec[0] = fout*dx
            fvec[1] = fout*dy
            fvec[2] = fout*dz

            hvec = np.cross(strength,fvec)

            return hvec

        def dipole3e(x,y,z,source,strength,k):
        #
        #  evalaute electric and magnetic field due
        #  to monochromatic electric dipole located at "source"
        #  with intensity "strength"

            evec = green3e(x,y,z,source,strength,k)
            evec = evec*1j*k
            hvec = green3m(x,y,z,source,strength,k)
            return evec,hvec
            
        def dipole3m(x,y,z,source,strength,k):
        #
        #  evalaute electric and magnetic field due
        #  to monochromatic magnetic dipole located at "source"
        #  with intensity "strength"
            evec = green3m(x,y,z,source,strength,k)
            hvec = green3e(x,y,z,source,strength,k)
            hvec = -hvec*1j*k
            return evec,hvec
            

        def dipole3eall(x,y,z,sources,strengths,k):
            ns = len(strengths)
            evec = np.zeros(3,dtype=np.complex128)
            hvec = np.zeros(3,dtype=np.complex128)

            for i in range(ns):
                evect,hvect = dipole3e(x,y,z,sources[i],strengths[i],k)
                evec = evec + evect
                hvec = hvec + hvect

        nodes = density_discr.nodes().with_queue(queue).get()
        source = [0.01,-0.03,0.02]
#        source = cl.array.to_device(queue,np.zeros(3))
#        source[0] = 0.01
#        source[1] =-0.03
#        source[2] = 0.02
        strength = np.ones(3)
       
#        evec = cl.array.to_device(queue,np.zeros((3,len(nodes[0])),dtype=np.complex128))
#        hvec = cl.array.to_device(queue,np.zeros((3,len(nodes[0])),dtype=np.complex128))

        evec = np.zeros((3,len(nodes[0])),dtype=np.complex128)
        hvec = np.zeros((3,len(nodes[0])),dtype=np.complex128)
        for i in range(len(nodes[0])):
            evec[:,i],hvec[:,i] = dipole3e(nodes[0][i],nodes[1][i],nodes[2][i],source,strength,k)
        print(np.shape(hvec))
        print(type(evec))
        print(type(hvec))

        evec = cl.array.to_device(queue,evec)
        hvec = cl.array.to_device(queue,hvec)

        bvp_rhs = bind(qbx, sym_rhs)(queue,Einc=evec,Hinc=hvec)
        print(np.shape(bvp_rhs))
        print(type(bvp_rhs))
#        print(bvp_rhs)
        1/-1

        bound_op = bind(qbx, sym_operator)

        from pytential.solve import gmres
        if 0:
            gmres_result = gmres(
                bound_op.scipy_op(queue, "sigma", dtype=np.complex128, k=k),
                bvp_rhs, tol=1e-8, progress=True,
                stall_iterations=0,
                hard_failure=True)

            sigma = gmres_result.solution

        fld_at_tgt = bind((qbx, PointsTarget(tgt_points)), sym_repr)(queue,
        sigma=bvp_rhs,k=k)
        fld_at_tgt = np.array([
            fi.get() for fi in fld_at_tgt
            ])
        print(fld_at_tgt)
        1/0

    # }}}

    #mlab.figure(bgcolor=(1, 1, 1))
    if 1:
        from meshmode.discretization.visualization import make_visualizer
        bdry_vis = make_visualizer(queue, density_discr, target_order)

        bdry_normals = bind(density_discr, sym.normal(3))(queue)\
                .as_vector(dtype=object)

        bdry_vis.write_vtk_file("source.vtu", [
            ("sigma", sigma),
            ("bdry_normals", bdry_normals),
            ])

        fplot = FieldPlotter(bbox_center, extent=2*bbox_size, npoints=(150, 150, 1))

        qbx_tgt_tol = qbx.copy(target_association_tolerance=0.1)
        from pytential.target import PointsTarget
        from pytential.qbx import QBXTargetAssociationFailedException

        rho_sym = sym.var("rho")

        try:
            fld_in_vol = bind(
                    (qbx_tgt_tol, PointsTarget(fplot.points)),
                    sym.make_obj_array([
                        sym.S(pde_op.kernel, rho_sym, k=sym.var("k"),
                            qbx_forced_limit=None),
                        sym.d_dx(3, sym.S(pde_op.kernel, rho_sym, k=sym.var("k"),
                            qbx_forced_limit=None)),
                        sym.d_dy(3, sym.S(pde_op.kernel, rho_sym, k=sym.var("k"),
                            qbx_forced_limit=None)),
                        sym.d_dz(3, sym.S(pde_op.kernel, rho_sym, k=sym.var("k"),
                            qbx_forced_limit=None)),
                        ])
                    )(queue, jt=jt, rho=rho, k=k)
        except QBXTargetAssociationFailedException as e:
            fplot.write_vtk_file(
                    "failed-targets.vts",
                    [
                        ("failed_targets", e.failed_target_flags.get(queue))
                        ])
            raise

        fld_in_vol = sym.make_obj_array(
            [fiv.get() for fiv in fld_in_vol])

        #fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
        fplot.write_vtk_file(
                "potential.vts",
                [
                    ("potential", fld_in_vol[0]),
                    ("grad", fld_in_vol[1:]),
                    ]
                )
Esempio n. 44
0
from pytential.discretization.qbx import make_upsampling_qbx_discr

discr = make_upsampling_qbx_discr(
        cl_ctx, mesh, target_order, qbx_order)

nodes = discr.nodes().with_queue(queue)

angle = cl.clmath.atan2(nodes[1], nodes[0])

from pytential import bind, sym
representation = sym.S(0, sym.var("sigma"))
op = representation

bc = cl.clmath.cos(mode_nr*angle)

bound_op = bind(discr, op)
from pytential.gmres import gmres
gmres_result = gmres(
        bound_op.scipy_op(queue, "sigma"),
        bc, tol=1e-14, progress=True,
        hard_failure=True)

import sys
sys.exit()

sigma = gmres_result.solution

fplot = FieldPlotter(np.zeros(2), extent=5, npoints=500)
from pytential.discretization.target import PointsTarget
fld_in_vol = bind(
        (discr, PointsTarget(fplot.points)),
Esempio n. 45
0
 def centers(self, target_discr, sign):
     from pytential import sym, bind
     with cl.CommandQueue(self.cl_context) as queue:
         return bind(target_discr,
                 sym.Nodes() + 2*sign*sym.area_element()*sym.normal())(queue) \
                         .as_vector(np.object)
Esempio n. 46
0
def main():
    import logging
    logger = logging.getLogger(__name__)
    logging.basicConfig(level=logging.WARNING)  # INFO for more progress info

    from meshmode.mesh.io import generate_gmsh, FileSource
    mesh = generate_gmsh(
            FileSource(cad_file_name), 2, order=2,
            other_options=["-string", "Mesh.CharacteristicLengthMax = %g;" % h])

    from meshmode.mesh.processing import perform_flips
    # Flip elements--gmsh generates inside-out geometry.
    mesh = perform_flips(mesh, np.ones(mesh.nelements))

    from meshmode.mesh.processing import find_bounding_box
    bbox_min, bbox_max = find_bounding_box(mesh)
    bbox_center = 0.5*(bbox_min+bbox_max)
    bbox_size = max(bbox_max-bbox_min) / 2

    logger.info("%d elements" % mesh.nelements)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))

    qbx, _ = QBXLayerPotentialSource(density_discr, 4*target_order, qbx_order,
            fmm_order=qbx_order + 3,
            target_association_tolerance=0.15).with_refinement()

    nodes = density_discr.nodes().with_queue(queue)

    angle = cl.clmath.atan2(nodes[1], nodes[0])

    from pytential import bind, sym
    #op = sym.d_dx(sym.S(kernel, sym.var("sigma"), qbx_forced_limit=None))
    op = sym.D(kernel, sym.var("sigma"), qbx_forced_limit=None)
    #op = sym.S(kernel, sym.var("sigma"), qbx_forced_limit=None)

    sigma = cl.clmath.cos(mode_nr*angle)
    if 0:
        sigma = 0*angle
        from random import randrange
        for i in range(5):
            sigma[randrange(len(sigma))] = 1

    if isinstance(kernel, HelmholtzKernel):
        sigma = sigma.astype(np.complex128)

    fplot = FieldPlotter(bbox_center, extent=3.5*bbox_size, npoints=150)

    from pytential.target import PointsTarget
    fld_in_vol = bind(
            (qbx, PointsTarget(fplot.points)),
            op)(queue, sigma=sigma, k=k).get()

    #fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
    fplot.write_vtk_file(
            "potential-3d.vts",
            [
                ("potential", fld_in_vol)
                ]
            )

    bdry_normals = bind(
            density_discr,
            sym.normal(density_discr.ambient_dim))(queue).as_vector(dtype=object)

    from meshmode.discretization.visualization import make_visualizer
    bdry_vis = make_visualizer(queue, density_discr, target_order)

    bdry_vis.write_vtk_file("source-3d.vtu", [
        ("sigma", sigma),
        ("bdry_normals", bdry_normals),
        ])
Esempio n. 47
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def test_sanity_single_element(ctx_getter, dim, order, visualize=False):
    pytest.importorskip("pytential")

    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    from modepy.tools import UNIT_VERTICES
    vertices = UNIT_VERTICES[dim].T.copy()

    center = np.empty(dim, np.float64)
    center.fill(-0.5)

    import modepy as mp
    from meshmode.mesh import SimplexElementGroup, Mesh
    mg = SimplexElementGroup(
            order=order,
            vertex_indices=np.arange(dim+1, dtype=np.int32).reshape(1, -1),
            nodes=mp.warp_and_blend_nodes(dim, order).reshape(dim, 1, -1),
            dim=dim)

    mesh = Mesh(vertices, [mg])

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            PolynomialWarpAndBlendGroupFactory
    vol_discr = Discretization(cl_ctx, mesh,
            PolynomialWarpAndBlendGroupFactory(order+3))

    # {{{ volume calculation check

    vol_x = vol_discr.nodes().with_queue(queue)

    vol_one = vol_x[0].copy()
    vol_one.fill(1)
    from pytential import norm, integral  # noqa

    from pytools import factorial
    true_vol = 1/factorial(dim) * 2**dim

    comp_vol = integral(vol_discr, queue, vol_one)
    rel_vol_err = abs(true_vol - comp_vol) / true_vol

    assert rel_vol_err < 1e-12

    # }}}

    # {{{ boundary discretization

    from meshmode.discretization.connection import make_boundary_restriction
    bdry_mesh, bdry_discr, bdry_connection = make_boundary_restriction(
            queue, vol_discr, PolynomialWarpAndBlendGroupFactory(order + 3))

    # }}}

    # {{{ visualizers

    from meshmode.discretization.visualization import make_visualizer
    #vol_vis = make_visualizer(queue, vol_discr, 4)
    bdry_vis = make_visualizer(queue, bdry_discr, 4)

    # }}}

    from pytential import bind, sym
    bdry_normals = bind(bdry_discr, sym.normal())(queue).as_vector(dtype=object)

    if visualize:
        bdry_vis.write_vtk_file("boundary.vtu", [
            ("bdry_normals", bdry_normals)
            ])

    from pytential import bind, sym
    normal_outward_check = bind(bdry_discr,
            sym.normal()
            |
            (sym.Nodes() + 0.5*sym.ones_vec(dim)),
            )(queue).as_scalar() > 0

    assert normal_outward_check.get().all(), normal_outward_check.get()
Esempio n. 48
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def main():
    import logging
    logging.basicConfig(level=logging.WARNING)  # INFO for more progress info

    cl_ctx = cl.create_some_context()
    queue = cl.CommandQueue(cl_ctx)

    from meshmode.mesh.generation import generate_torus

    rout = 10
    rin = 1
    if 1:
        base_mesh = generate_torus(
                rout, rin, 40, 4,
                mesh_order)

        from meshmode.mesh.processing import affine_map, merge_disjoint_meshes
        # nx = 1
        # ny = 1
        nz = 1
        dz = 0
        meshes = [
                affine_map(
                    base_mesh,
                    A=np.diag([1, 1, 1]),
                    b=np.array([0, 0, iz*dz]))
                for iz in range(nz)]

        mesh = merge_disjoint_meshes(meshes, single_group=True)

        if 0:
            from meshmode.mesh.visualization import draw_curve
            draw_curve(mesh)
            import matplotlib.pyplot as plt
            plt.show()

    pre_density_discr = Discretization(
            cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))

    from pytential.qbx import (
            QBXLayerPotentialSource, QBXTargetAssociationFailedException)
    qbx, _ = QBXLayerPotentialSource(
            pre_density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
            fmm_order=fmm_order
            ).with_refinement()
    density_discr = qbx.density_discr

    # {{{ describe bvp

    from sumpy.kernel import LaplaceKernel
    kernel = LaplaceKernel(3)

    cse = sym.cse

    sigma_sym = sym.var("sigma")
    #sqrt_w = sym.sqrt_jac_q_weight(3)
    sqrt_w = 1
    inv_sqrt_w_sigma = cse(sigma_sym/sqrt_w)

    # -1 for interior Dirichlet
    # +1 for exterior Dirichlet
    loc_sign = +1

    bdry_op_sym = (loc_sign*0.5*sigma_sym
            + sqrt_w*(
                sym.S(kernel, inv_sqrt_w_sigma)
                + sym.D(kernel, inv_sqrt_w_sigma)
                ))

    # }}}

    bound_op = bind(qbx, bdry_op_sym)

    # {{{ fix rhs and solve

    nodes = density_discr.nodes().with_queue(queue)
    source = np.array([rout, 0, 0])

    def u_incoming_func(x):
        #        return 1/cl.clmath.sqrt( (x[0] - source[0])**2
        #                                +(x[1] - source[1])**2
        #                                +(x[2] - source[2])**2 )
        return 1.0/la.norm(x.get()-source[:, None], axis=0)

    bc = cl.array.to_device(queue, u_incoming_func(nodes))

    bvp_rhs = bind(qbx, sqrt_w*sym.var("bc"))(queue, bc=bc)

    from pytential.solve import gmres
    gmres_result = gmres(
            bound_op.scipy_op(queue, "sigma", dtype=np.float64),
            bvp_rhs, tol=1e-14, progress=True,
            stall_iterations=0,
            hard_failure=True)

    sigma = bind(qbx, sym.var("sigma")/sqrt_w)(queue, sigma=gmres_result.solution)

    # }}}

    from meshmode.discretization.visualization import make_visualizer
    bdry_vis = make_visualizer(queue, density_discr, 20)
    bdry_vis.write_vtk_file("laplace.vtu", [
        ("sigma", sigma),
        ])

    # {{{ postprocess/visualize

    repr_kwargs = dict(qbx_forced_limit=None)
    representation_sym = (
            sym.S(kernel, inv_sqrt_w_sigma, **repr_kwargs)
            + sym.D(kernel, inv_sqrt_w_sigma, **repr_kwargs))

    from sumpy.visualization import FieldPlotter
    fplot = FieldPlotter(np.zeros(3), extent=20, npoints=50)

    targets = cl.array.to_device(queue, fplot.points)

    qbx_stick_out = qbx.copy(target_stick_out_factor=0.2)

    try:
        fld_in_vol = bind(
                (qbx_stick_out, PointsTarget(targets)),
                representation_sym)(queue, sigma=sigma).get()
    except QBXTargetAssociationFailedException as e:
        fplot.write_vtk_file(
                "failed-targets.vts",
                [
                    ("failed", e.failed_target_flags.get(queue))
                    ]
                )
        raise

    #fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
    fplot.write_vtk_file(
            "potential-laplace-3d.vts",
            [
                ("potential", fld_in_vol),
                ]
            )
Esempio n. 49
0
        np.linspace(0, 1, nelements+1),
        target_order)

from pytential.discretization.qbx import make_upsampling_qbx_discr

discr = make_upsampling_qbx_discr(
        cl_ctx, mesh, target_order, qbx_order)

nodes = discr.nodes().with_queue(queue)

angle = cl.clmath.atan2(nodes[1], nodes[0])

from pytential import bind, sym
representation = sym.S(0, sym.var("sigma"))
op = representation

bc = cl.clmath.cos(mode_nr*angle)

bound_op = bind(discr, op)

from sumpy.tools import build_matrix
mat = build_matrix(bound_op.scipy_op(queue, "sigma"))

w, v = la.eig(mat)

import matplotlib.pyplot as pt
pt.plot(w.real, w.imag, "x")
pt.rc("font", size=20)
pt.grid()
pt.show()
Esempio n. 50
0
def run_dielectric_test(cl_ctx, queue, nelements, qbx_order,
        op_class, mode,
        k0=3, k1=2.9, mesh_order=10,
        bdry_quad_order=None, bdry_ovsmp_quad_order=None,
        use_l2_weighting=False,
        fmm_order=None, visualize=False):

    if fmm_order is None:
        fmm_order = qbx_order * 2
    if bdry_quad_order is None:
        bdry_quad_order = mesh_order
    if bdry_ovsmp_quad_order is None:
        bdry_ovsmp_quad_order = 4*bdry_quad_order

    from meshmode.mesh.generation import ellipse, make_curve_mesh
    from functools import partial
    mesh = make_curve_mesh(
            partial(ellipse, 3),
            np.linspace(0, 1, nelements+1),
            mesh_order)

    density_discr = Discretization(
            cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))

    logger.info("%d elements" % mesh.nelements)

    # from meshmode.discretization.visualization import make_visualizer
    # bdry_vis = make_visualizer(queue, density_discr, 20)

    # {{{ solve bvp

    from sumpy.kernel import HelmholtzKernel, AxisTargetDerivative
    kernel = HelmholtzKernel(2)

    beta = 2.5
    K0 = np.sqrt(k0**2-beta**2)  # noqa
    K1 = np.sqrt(k1**2-beta**2)  # noqa

    pde_op = op_class(
            mode,
            k_vacuum=1,
            interfaces=((0, 1, sym.DEFAULT_SOURCE),),
            domain_k_exprs=(k0, k1),
            beta=beta,
            use_l2_weighting=use_l2_weighting)

    op_unknown_sym = pde_op.make_unknown("unknown")

    representation0_sym = pde_op.representation(op_unknown_sym, 0)
    representation1_sym = pde_op.representation(op_unknown_sym, 1)

    from pytential.qbx import QBXLayerPotentialSource
    qbx = QBXLayerPotentialSource(
            density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
            fmm_order=fmm_order
            ).with_refinement()

    #print(sym.pretty(pde_op.operator(op_unknown_sym)))
    #1/0
    bound_pde_op = bind(qbx, pde_op.operator(op_unknown_sym))

    e_factor = float(pde_op.ez_enabled)
    h_factor = float(pde_op.hz_enabled)

    e_sources_0 = make_obj_array(list(np.array([
        [0.1, 0.2]
        ]).T.copy()))
    e_strengths_0 = np.array([1*e_factor])
    e_sources_1 = make_obj_array(list(np.array([
        [4, 4]
        ]).T.copy()))
    e_strengths_1 = np.array([1*e_factor])

    h_sources_0 = make_obj_array(list(np.array([
        [0.2, 0.1]
        ]).T.copy()))
    h_strengths_0 = np.array([1*h_factor])
    h_sources_1 = make_obj_array(list(np.array([
        [4, 5]
        ]).T.copy()))
    h_strengths_1 = np.array([1*h_factor])

    kernel_grad = [
        AxisTargetDerivative(i, kernel) for i in range(density_discr.ambient_dim)]

    from sumpy.p2p import P2P
    pot_p2p = P2P(cl_ctx, [kernel], exclude_self=False)
    pot_p2p_grad = P2P(cl_ctx, kernel_grad, exclude_self=False)

    normal = bind(density_discr, sym.normal())(queue).as_vector(np.object)
    tangent = bind(
        density_discr,
        sym.pseudoscalar()/sym.area_element())(queue).as_vector(np.object)

    _, (E0,) = pot_p2p(queue, density_discr.nodes(), e_sources_0, [e_strengths_0],
                    out_host=False, k=K0)
    _, (E1,) = pot_p2p(queue, density_discr.nodes(), e_sources_1, [e_strengths_1],
                    out_host=False, k=K1)
    _, (grad0_E0, grad1_E0) = pot_p2p_grad(
        queue, density_discr.nodes(), e_sources_0, [e_strengths_0],
        out_host=False, k=K0)
    _, (grad0_E1, grad1_E1) = pot_p2p_grad(
        queue, density_discr.nodes(), e_sources_1, [e_strengths_1],
        out_host=False, k=K1)

    _, (H0,) = pot_p2p(queue, density_discr.nodes(), h_sources_0, [h_strengths_0],
                    out_host=False, k=K0)
    _, (H1,) = pot_p2p(queue, density_discr.nodes(), h_sources_1, [h_strengths_1],
                    out_host=False, k=K1)
    _, (grad0_H0, grad1_H0) = pot_p2p_grad(
        queue, density_discr.nodes(), h_sources_0, [h_strengths_0],
        out_host=False, k=K0)
    _, (grad0_H1, grad1_H1) = pot_p2p_grad(
        queue, density_discr.nodes(), h_sources_1, [h_strengths_1],
        out_host=False, k=K1)

    E0_dntarget = (grad0_E0*normal[0] + grad1_E0*normal[1])  # noqa
    E1_dntarget = (grad0_E1*normal[0] + grad1_E1*normal[1])  # noqa

    H0_dntarget = (grad0_H0*normal[0] + grad1_H0*normal[1])  # noqa
    H1_dntarget = (grad0_H1*normal[0] + grad1_H1*normal[1])  # noqa

    E0_dttarget = (grad0_E0*tangent[0] + grad1_E0*tangent[1])  # noqa
    E1_dttarget = (grad0_E1*tangent[0] + grad1_E1*tangent[1])  # noqa

    H0_dttarget = (grad0_H0*tangent[0] + grad1_H0*tangent[1])  # noqa
    H1_dttarget = (grad0_H1*tangent[0] + grad1_H1*tangent[1])  # noqa

    sqrt_w = bind(density_discr, sym.sqrt_jac_q_weight())(queue)

    bvp_rhs = np.zeros(len(pde_op.bcs), dtype=np.object)
    for i_bc, terms in enumerate(pde_op.bcs):
        for term in terms:
            assert term.i_interface == 0
            if term.field_kind == pde_op.field_kind_e:

                if term.direction == pde_op.dir_none:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * E0
                        + term.coeff_inner * E1)
                elif term.direction == pde_op.dir_normal:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * E0_dntarget
                        + term.coeff_inner * E1_dntarget)
                elif term.direction == pde_op.dir_tangential:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * E0_dttarget
                        + term.coeff_inner * E1_dttarget)
                else:
                    raise NotImplementedError("direction spec in RHS")

            elif term.field_kind == pde_op.field_kind_h:
                if term.direction == pde_op.dir_none:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * H0
                        + term.coeff_inner * H1)
                elif term.direction == pde_op.dir_normal:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * H0_dntarget
                        + term.coeff_inner * H1_dntarget)
                elif term.direction == pde_op.dir_tangential:
                    bvp_rhs[i_bc] += (
                        term.coeff_outer * H0_dttarget
                        + term.coeff_inner * H1_dttarget)
                else:
                    raise NotImplementedError("direction spec in RHS")

            if use_l2_weighting:
                bvp_rhs[i_bc] *= sqrt_w

    scipy_op = bound_pde_op.scipy_op(queue, "unknown",
            domains=[sym.DEFAULT_TARGET]*len(pde_op.bcs), K0=K0, K1=K1,
            dtype=np.complex128)

    if mode == "tem" or op_class is SRep:
        from sumpy.tools import vector_from_device, vector_to_device
        from pytential.solve import lu
        unknown = lu(scipy_op, vector_from_device(queue, bvp_rhs))
        unknown = vector_to_device(queue, unknown)

    else:
        from pytential.solve import gmres
        gmres_result = gmres(scipy_op,
                bvp_rhs, tol=1e-14, progress=True,
                hard_failure=True, stall_iterations=0)

        unknown = gmres_result.solution

    # }}}

    targets_0 = make_obj_array(list(np.array([
        [3.2 + t, -4]
        for t in [0, 0.5, 1]
        ]).T.copy()))
    targets_1 = make_obj_array(list(np.array([
        [t*-0.3, t*-0.2]
        for t in [0, 0.5, 1]
        ]).T.copy()))

    from pytential.target import PointsTarget
    from sumpy.tools import vector_from_device
    F0_tgt = vector_from_device(queue, bind(  # noqa
            (qbx, PointsTarget(targets_0)),
            representation0_sym)(queue, unknown=unknown, K0=K0, K1=K1))
    F1_tgt = vector_from_device(queue, bind(  # noqa
            (qbx, PointsTarget(targets_1)),
            representation1_sym)(queue, unknown=unknown, K0=K0, K1=K1))

    _, (E0_tgt_true,) = pot_p2p(queue, targets_0, e_sources_0, [e_strengths_0],
                    out_host=True, k=K0)
    _, (E1_tgt_true,) = pot_p2p(queue, targets_1, e_sources_1, [e_strengths_1],
                    out_host=True, k=K1)

    _, (H0_tgt_true,) = pot_p2p(queue, targets_0, h_sources_0, [h_strengths_0],
                    out_host=True, k=K0)
    _, (H1_tgt_true,) = pot_p2p(queue, targets_1, h_sources_1, [h_strengths_1],
                    out_host=True, k=K1)

    err_F0_total = 0  # noqa
    err_F1_total = 0  # noqa

    i_field = 0

    def vec_norm(ary):
        return la.norm(ary.reshape(-1))

    def field_kind_to_string(field_kind):
        return {pde_op.field_kind_e: "E", pde_op.field_kind_h: "H"}[field_kind]

    for field_kind in pde_op.field_kinds:
        if not pde_op.is_field_present(field_kind):
            continue

        if field_kind == pde_op.field_kind_e:
            F0_tgt_true = E0_tgt_true  # noqa
            F1_tgt_true = E1_tgt_true  # noqa
        elif field_kind == pde_op.field_kind_h:
            F0_tgt_true = H0_tgt_true  # noqa
            F1_tgt_true = H1_tgt_true  # noqa
        else:
            assert False

        abs_err_F0 = vec_norm(F0_tgt[i_field] - F0_tgt_true)  # noqa
        abs_err_F1 = vec_norm(F1_tgt[i_field] - F1_tgt_true)  # noqa

        rel_err_F0 = abs_err_F0/vec_norm(F0_tgt_true)  # noqa
        rel_err_F1 = abs_err_F1/vec_norm(F1_tgt_true)  # noqa

        err_F0_total = max(rel_err_F0, err_F0_total)  # noqa
        err_F1_total = max(rel_err_F1, err_F1_total)  # noqa

        print("Abs Err %s0" % field_kind_to_string(field_kind), abs_err_F0)
        print("Abs Err %s1" % field_kind_to_string(field_kind), abs_err_F1)

        print("Rel Err %s0" % field_kind_to_string(field_kind), rel_err_F0)
        print("Rel Err %s1" % field_kind_to_string(field_kind), rel_err_F1)

        i_field += 1

    if visualize:
        from sumpy.visualization import FieldPlotter
        fplot = FieldPlotter(np.zeros(2), extent=5, npoints=300)
        from pytential.target import PointsTarget
        fld0 = bind(
                (qbx, PointsTarget(fplot.points)),
                representation0_sym)(queue, unknown=unknown, K0=K0)
        fld1 = bind(
                (qbx, PointsTarget(fplot.points)),
                representation1_sym)(queue, unknown=unknown, K1=K1)

        comp_fields = []
        i_field = 0
        for field_kind in pde_op.field_kinds:
            if not pde_op.is_field_present(field_kind):
                continue

            fld_str = field_kind_to_string(field_kind)
            comp_fields.extend([
                ("%s_fld0" % fld_str, fld0[i_field].get()),
                ("%s_fld1" % fld_str, fld1[i_field].get()),
                ])

            i_field += 0

        low_order_qbx = QBXLayerPotentialSource(
                density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=2,
                fmm_order=3).with_refinement()
        from sumpy.kernel import LaplaceKernel
        from pytential.target import PointsTarget
        ones = (cl.array.empty(queue, (density_discr.nnodes,), dtype=np.float64)
                .fill(1))
        ind_func = - bind((low_order_qbx, PointsTarget(fplot.points)),
                sym.D(LaplaceKernel(2), sym.var("u")))(
                        queue, u=ones).get()

        _, (e_fld0_true,) = pot_p2p(
                queue, fplot.points, e_sources_0, [e_strengths_0],
                out_host=True, k=K0)
        _, (e_fld1_true,) = pot_p2p(
                queue, fplot.points, e_sources_1, [e_strengths_1],
                out_host=True, k=K1)
        _, (h_fld0_true,) = pot_p2p(
                queue, fplot.points, h_sources_0, [h_strengths_0],
                out_host=True, k=K0)
        _, (h_fld1_true,) = pot_p2p(
                queue, fplot.points, h_sources_1, [h_strengths_1],
                out_host=True, k=K1)

        #fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
        fplot.write_vtk_file(
                "potential-n%d.vts" % nelements,
                [
                    ("e_fld0_true", e_fld0_true),
                    ("e_fld1_true", e_fld1_true),
                    ("h_fld0_true", h_fld0_true),
                    ("h_fld1_true", h_fld1_true),
                    ("ind", ind_func),
                    ] + comp_fields
                )

    return err_F0_total, err_F1_total
Esempio n. 51
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def test_off_surface_eval_vs_direct(ctx_getter,  do_plot=False):
    logging.basicConfig(level=logging.INFO)

    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    nelements = 300
    target_order = 8
    qbx_order = 3

    mesh = make_curve_mesh(WobblyCircle.random(8, seed=30),
                np.linspace(0, 1, nelements+1),
                target_order)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    pre_density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    direct_qbx, _ = QBXLayerPotentialSource(
            pre_density_discr, 4*target_order, qbx_order,
            fmm_order=False,
            target_association_tolerance=0.05,
            ).with_refinement()
    fmm_qbx, _ = QBXLayerPotentialSource(
            pre_density_discr, 4*target_order, qbx_order,
            fmm_order=qbx_order + 3,
            _expansions_in_tree_have_extent=True,
            target_association_tolerance=0.05,
            ).with_refinement()

    fplot = FieldPlotter(np.zeros(2), extent=5, npoints=1000)
    from pytential.target import PointsTarget
    ptarget = PointsTarget(fplot.points)
    from sumpy.kernel import LaplaceKernel

    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=None)

    from pytential.qbx import QBXTargetAssociationFailedException
    try:
        direct_density_discr = direct_qbx.density_discr
        direct_sigma = direct_density_discr.zeros(queue) + 1
        direct_fld_in_vol = bind((direct_qbx, ptarget), op)(
                queue, sigma=direct_sigma)

    except QBXTargetAssociationFailedException as e:
        fplot.show_scalar_in_matplotlib(e.failed_target_flags.get(queue))
        import matplotlib.pyplot as pt
        pt.show()
        raise

    fmm_density_discr = fmm_qbx.density_discr
    fmm_sigma = fmm_density_discr.zeros(queue) + 1
    fmm_fld_in_vol = bind((fmm_qbx, ptarget), op)(queue, sigma=fmm_sigma)

    err = cl.clmath.fabs(fmm_fld_in_vol - direct_fld_in_vol)

    linf_err = cl.array.max(err).get()
    print("l_inf error:", linf_err)

    if do_plot:
        #fplot.show_scalar_in_mayavi(0.1*.get(queue))
        fplot.write_vtk_file("potential.vts", [
            ("fmm_fld_in_vol", fmm_fld_in_vol.get(queue)),
            ("direct_fld_in_vol", direct_fld_in_vol.get(queue))
            ])

    assert linf_err < 1e-3
Esempio n. 52
0
def run_int_eq_test(
        cl_ctx, queue, curve_f, nelements, qbx_order, bc_type, loc_sign, k,
        target_order, source_order):

    mesh = make_curve_mesh(curve_f,
            np.linspace(0, 1, nelements+1),
            target_order)

    if 0:
        from pytential.visualization import show_mesh
        show_mesh(mesh)

        pt.gca().set_aspect("equal")
        pt.show()

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory
    density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))

    if source_order is None:
        source_order = 4*target_order

    qbx = QBXLayerPotentialSource(
            density_discr, fine_order=source_order, qbx_order=qbx_order,
            # Don't use FMM for now
            fmm_order=False)

    # {{{ set up operator

    from pytential.symbolic.pde.scalar import (
            DirichletOperator,
            NeumannOperator)

    from sumpy.kernel import LaplaceKernel, HelmholtzKernel, AxisTargetDerivative
    if k:
        knl = HelmholtzKernel(2)
        knl_kwargs = {"k": k}
    else:
        knl = LaplaceKernel(2)
        knl_kwargs = {}

    if knl.is_complex_valued:
        dtype = np.complex128
    else:
        dtype = np.float64

    if bc_type == "dirichlet":
        op = DirichletOperator((knl, knl_kwargs), loc_sign, use_l2_weighting=True)
    elif bc_type == "neumann":
        op = NeumannOperator((knl, knl_kwargs), loc_sign, use_l2_weighting=True,
                 use_improved_operator=False)
    else:
        assert False

    op_u = op.operator(sym.var("u"))

    # }}}

    # {{{ set up test data

    inner_radius = 0.1
    outer_radius = 2

    if loc_sign < 0:
        test_src_geo_radius = outer_radius
        test_tgt_geo_radius = inner_radius
    else:
        test_src_geo_radius = inner_radius
        test_tgt_geo_radius = outer_radius

    point_sources = make_circular_point_group(10, test_src_geo_radius,
            func=lambda x: x**1.5)
    test_targets = make_circular_point_group(20, test_tgt_geo_radius)

    np.random.seed(22)
    source_charges = np.random.randn(point_sources.shape[1])
    source_charges[-1] = -np.sum(source_charges[:-1])
    source_charges = source_charges.astype(dtype)
    assert np.sum(source_charges) < 1e-15

    # }}}

    if 0:
        # show geometry, centers, normals
        nodes_h = density_discr.nodes().get(queue=queue)
        pt.plot(nodes_h[0], nodes_h[1], "x-")
        normal = bind(density_discr, sym.normal())(queue).as_vector(np.object)
        pt.quiver(nodes_h[0], nodes_h[1], normal[0].get(queue), normal[1].get(queue))
        pt.gca().set_aspect("equal")
        pt.show()

    # {{{ establish BCs

    from sumpy.p2p import P2P
    pot_p2p = P2P(cl_ctx,
            [knl], exclude_self=False, value_dtypes=dtype)

    evt, (test_direct,) = pot_p2p(
            queue, test_targets, point_sources, [source_charges],
            out_host=False, **knl_kwargs)

    nodes = density_discr.nodes()

    evt, (src_pot,) = pot_p2p(
            queue, nodes, point_sources, [source_charges],
            **knl_kwargs)

    grad_p2p = P2P(cl_ctx,
            [AxisTargetDerivative(0, knl), AxisTargetDerivative(1, knl)],
            exclude_self=False, value_dtypes=dtype)
    evt, (src_grad0, src_grad1) = grad_p2p(
            queue, nodes, point_sources, [source_charges],
            **knl_kwargs)

    if bc_type == "dirichlet":
        bc = src_pot
    elif bc_type == "neumann":
        normal = bind(density_discr, sym.normal())(queue).as_vector(np.object)
        bc = (src_grad0*normal[0] + src_grad1*normal[1])

    # }}}

    # {{{ solve

    bound_op = bind(qbx, op_u)

    rhs = bind(density_discr, op.prepare_rhs(sym.var("bc")))(queue, bc=bc)

    from pytential.solve import gmres
    gmres_result = gmres(
            bound_op.scipy_op(queue, "u", k=k),
            rhs, tol=1e-14, progress=True,
            hard_failure=False)

    u = gmres_result.solution
    print("gmres state:", gmres_result.state)

    if 0:
        # {{{ build matrix for spectrum check

        from sumpy.tools import build_matrix
        mat = build_matrix(bound_op.scipy_op("u"))
        w, v = la.eig(mat)
        if 0:
            pt.imshow(np.log10(1e-20+np.abs(mat)))
            pt.colorbar()
            pt.show()

        #assert abs(s[-1]) < 1e-13, "h
        #assert abs(s[-2]) > 1e-7
        #from pudb import set_trace; set_trace()

        # }}}

    # }}}

    # {{{ error check

    from pytential.target import PointsTarget

    bound_tgt_op = bind((qbx, PointsTarget(test_targets)),
            op.representation(sym.var("u")))

    test_via_bdry = bound_tgt_op(queue, u=u, k=k)

    err = test_direct-test_via_bdry

    err = err.get()
    test_direct = test_direct.get()
    test_via_bdry = test_via_bdry.get()

    # {{{ remove effect of net source charge

    if k == 0 and bc_type == "neumann" and loc_sign == -1:
        # remove constant offset in interior Laplace Neumann error
        tgt_ones = np.ones_like(test_direct)
        tgt_ones = tgt_ones/la.norm(tgt_ones)
        err = err - np.vdot(tgt_ones, err)*tgt_ones

    # }}}

    rel_err_2 = la.norm(err)/la.norm(test_direct)
    rel_err_inf = la.norm(err, np.inf)/la.norm(test_direct, np.inf)

    # }}}

    print("rel_err_2: %g rel_err_inf: %g" % (rel_err_2, rel_err_inf))

    # {{{ test tangential derivative

    bound_t_deriv_op = bind(qbx,
            op.representation(
                sym.var("u"), map_potentials=sym.tangential_derivative,
                qbx_forced_limit=loc_sign))

    #print(bound_t_deriv_op.code)

    tang_deriv_from_src = bound_t_deriv_op(queue, u=u).as_scalar().get()

    tangent = bind(
            density_discr,
            sym.pseudoscalar()/sym.area_element())(queue).as_vector(np.object)

    tang_deriv_ref = (src_grad0 * tangent[0] + src_grad1 * tangent[1]).get()

    if 0:
        pt.plot(tang_deriv_ref.real)
        pt.plot(tang_deriv_from_src.real)
        pt.show()

    td_err = tang_deriv_from_src - tang_deriv_ref

    rel_td_err_inf = la.norm(td_err, np.inf)/la.norm(tang_deriv_ref, np.inf)

    print("rel_td_err_inf: %g" % rel_td_err_inf)

    # }}}

    # {{{ plotting

    if 0:
        fplot = FieldPlotter(np.zeros(2),
                extent=1.25*2*max(test_src_geo_radius, test_tgt_geo_radius),
                npoints=200)

        #pt.plot(u)
        #pt.show()

        evt, (fld_from_src,) = pot_p2p(
                queue, fplot.points, point_sources, [source_charges],
                **knl_kwargs)
        fld_from_bdry = bind(
                (qbx, PointsTarget(fplot.points)),
                op.representation(sym.var("u"))
                )(queue, u=u, k=k)
        fld_from_src = fld_from_src.get()
        fld_from_bdry = fld_from_bdry.get()

        nodes = density_discr.nodes().get(queue=queue)

        def prep():
            pt.plot(point_sources[0], point_sources[1], "o",
                    label="Monopole 'Point Charges'")
            pt.plot(test_targets[0], test_targets[1], "v",
                    label="Observation Points")
            pt.plot(nodes[0], nodes[1], "k-",
                    label=r"$\Gamma$")

        from matplotlib.cm import get_cmap
        cmap = get_cmap()
        cmap._init()
        if 0:
            cmap._lut[(cmap.N*99)//100:, -1] = 0  # make last percent transparent?

        prep()
        if 1:
            pt.subplot(131)
            pt.title("Field error (loc_sign=%s)" % loc_sign)
            log_err = np.log10(1e-20+np.abs(fld_from_src-fld_from_bdry))
            log_err = np.minimum(-3, log_err)
            fplot.show_scalar_in_matplotlib(log_err, cmap=cmap)

            #from matplotlib.colors import Normalize
            #im.set_norm(Normalize(vmin=-6, vmax=1))

            cb = pt.colorbar(shrink=0.9)
            cb.set_label(r"$\log_{10}(\mathdefault{Error})$")

        if 1:
            pt.subplot(132)
            prep()
            pt.title("Source Field")
            fplot.show_scalar_in_matplotlib(
                    fld_from_src.real, max_val=3)

            pt.colorbar(shrink=0.9)
        if 1:
            pt.subplot(133)
            prep()
            pt.title("Solved Field")
            fplot.show_scalar_in_matplotlib(
                    fld_from_bdry.real, max_val=3)

            pt.colorbar(shrink=0.9)

        # total field
        #fplot.show_scalar_in_matplotlib(
        #fld_from_src.real+fld_from_bdry.real, max_val=0.1)

        #pt.colorbar()

        pt.legend(loc="best", prop=dict(size=15))
        from matplotlib.ticker import NullFormatter
        pt.gca().xaxis.set_major_formatter(NullFormatter())
        pt.gca().yaxis.set_major_formatter(NullFormatter())

        pt.gca().set_aspect("equal")

        if 0:
            border_factor_top = 0.9
            border_factor = 0.3

            xl, xh = pt.xlim()
            xhsize = 0.5*(xh-xl)
            pt.xlim(xl-border_factor*xhsize, xh+border_factor*xhsize)

            yl, yh = pt.ylim()
            yhsize = 0.5*(yh-yl)
            pt.ylim(yl-border_factor_top*yhsize, yh+border_factor*yhsize)

        #pt.savefig("helmholtz.pdf", dpi=600)
        pt.show()

        # }}}

    class Result(Record):
        pass

    return Result(
            rel_err_2=rel_err_2,
            rel_err_inf=rel_err_inf,
            rel_td_err_inf=rel_td_err_inf,
            gmres_result=gmres_result)
Esempio n. 53
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def test_perf_data_gathering(ctx_getter, n_arms=5):
    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    target_order = 8

    starfish_func = NArmedStarfish(n_arms, 0.8)
    mesh = make_curve_mesh(
            starfish_func,
            np.linspace(0, 1, n_arms * 30),
            target_order)

    sigma_sym = sym.var("sigma")

    # The kernel doesn't really matter here
    from sumpy.kernel import LaplaceKernel
    k_sym = LaplaceKernel(mesh.ambient_dim)

    sym_op = sym.S(k_sym, sigma_sym, qbx_forced_limit=+1)

    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import (
            InterpolatoryQuadratureSimplexGroupFactory)
    pre_density_discr = Discretization(
            queue.context, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(target_order))

    results = []

    def inspect_geo_data(insn, bound_expr, geo_data):
        from pytential.qbx.fmm import assemble_performance_data
        perf_data = assemble_performance_data(geo_data, uses_pde_expansions=True)
        results.append(perf_data)

        return False  # no need to do the actual FMM

    from pytential.qbx import QBXLayerPotentialSource
    lpot_source = QBXLayerPotentialSource(
            pre_density_discr, 4*target_order,
            # qbx order and fmm order don't really matter
            10, fmm_order=10,
            _expansions_in_tree_have_extent=True,
            _expansion_stick_out_factor=0.5,
            geometry_data_inspector=inspect_geo_data,
            target_association_tolerance=1e-10,
            )

    lpot_source, _ = lpot_source.with_refinement()

    density_discr = lpot_source.density_discr

    if 0:
        from meshmode.discretization.visualization import draw_curve
        draw_curve(density_discr)
        import matplotlib.pyplot as plt
        plt.show()

    nodes = density_discr.nodes().with_queue(queue)
    sigma = cl.clmath.sin(10 * nodes[0])

    bind(lpot_source, sym_op)(queue, sigma=sigma)
Esempio n. 54
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def test_3d_jump_relations(ctx_factory, relation, visualize=False):
    # logging.basicConfig(level=logging.INFO)

    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)

    if relation == "div_s":
        target_order = 3
    else:
        target_order = 4

    qbx_order = target_order

    from pytools.convergence import EOCRecorder
    eoc_rec = EOCRecorder()

    for nel_factor in [6, 10, 14]:
        from meshmode.mesh.generation import generate_torus
        mesh = generate_torus(
                5, 2, order=target_order,
                n_outer=2*nel_factor, n_inner=nel_factor)

        from meshmode.discretization import Discretization
        from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory
        pre_discr = Discretization(
                cl_ctx, mesh,
                InterpolatoryQuadratureSimplexGroupFactory(3))

        from pytential.qbx import QBXLayerPotentialSource
        qbx, _ = QBXLayerPotentialSource(
                pre_discr, fine_order=4*target_order,
                qbx_order=qbx_order,
                fmm_order=qbx_order + 5,
                fmm_backend="fmmlib"
                ).with_refinement()

        from sumpy.kernel import LaplaceKernel
        knl = LaplaceKernel(3)

        def nxcurlS(qbx_forced_limit):

            return sym.n_cross(sym.curl(sym.S(
                knl,
                sym.cse(sym.tangential_to_xyz(density_sym), "jxyz"),
                qbx_forced_limit=qbx_forced_limit)))

        x, y, z = qbx.density_discr.nodes().with_queue(queue)
        m = cl.clmath

        if relation == "nxcurls":
            density_sym = sym.make_sym_vector("density", 2)

            jump_identity_sym = (
                    nxcurlS(+1)
                    - (nxcurlS("avg") + 0.5*sym.tangential_to_xyz(density_sym)))

            # The tangential coordinate system is element-local, so we can't just
            # conjure up some globally smooth functions, interpret their values
            # in the tangential coordinate system, and be done. Instead, generate
            # an XYZ function and project it.
            density = bind(
                    qbx,
                    sym.xyz_to_tangential(sym.make_sym_vector("jxyz", 3)))(
                            queue,
                            jxyz=sym.make_obj_array([
                                m.cos(0.5*x) * m.cos(0.5*y) * m.cos(0.5*z),
                                m.sin(0.5*x) * m.cos(0.5*y) * m.sin(0.5*z),
                                m.sin(0.5*x) * m.cos(0.5*y) * m.cos(0.5*z),
                                ]))

        elif relation == "sp":

            density = m.cos(2*x) * m.cos(2*y) * m.cos(z)
            density_sym = sym.var("density")

            jump_identity_sym = (
                    sym.Sp(knl, density_sym, qbx_forced_limit=+1)
                    - (sym.Sp(knl, density_sym, qbx_forced_limit="avg")
                        - 0.5*density_sym))

        elif relation == "div_s":

            density = m.cos(2*x) * m.cos(2*y) * m.cos(z)
            density_sym = sym.var("density")

            jump_identity_sym = (
                    sym.div(sym.S(knl, sym.normal(3).as_vector()*density_sym,
                        qbx_forced_limit="avg"))
                    + sym.D(knl, density_sym, qbx_forced_limit="avg"))

        else:
            raise ValueError("unexpected value of 'relation': %s" % relation)

        bound_jump_identity = bind(qbx, jump_identity_sym)
        jump_identity = bound_jump_identity(queue, density=density)

        err = (
                norm(qbx, queue, jump_identity, np.inf)
                / norm(qbx, queue, density, np.inf))
        print("ERROR", qbx.h_max, err)

        eoc_rec.add_data_point(qbx.h_max, err)

        # {{{ visualization

        if visualize and relation == "nxcurls":
            nxcurlS_ext = bind(qbx, nxcurlS(+1))(queue, density=density)
            nxcurlS_avg = bind(qbx, nxcurlS("avg"))(queue, density=density)
            jtxyz = bind(qbx, sym.tangential_to_xyz(density_sym))(
                    queue, density=density)

            from meshmode.discretization.visualization import make_visualizer
            bdry_vis = make_visualizer(queue, qbx.density_discr, target_order+3)

            bdry_normals = bind(qbx, sym.normal(3))(queue)\
                    .as_vector(dtype=object)

            bdry_vis.write_vtk_file("source-%s.vtu" % nel_factor, [
                ("jt", jtxyz),
                ("nxcurlS_ext", nxcurlS_ext),
                ("nxcurlS_avg", nxcurlS_avg),
                ("bdry_normals", bdry_normals),
                ])

        if visualize and relation == "sp":
            sp_ext = bind(qbx, sym.Sp(knl, density_sym, qbx_forced_limit=+1))(
                    queue, density=density)
            sp_avg = bind(qbx, sym.Sp(knl, density_sym, qbx_forced_limit="avg"))(
                    queue, density=density)

            from meshmode.discretization.visualization import make_visualizer
            bdry_vis = make_visualizer(queue, qbx.density_discr, target_order+3)

            bdry_normals = bind(qbx, sym.normal(3))(queue)\
                    .as_vector(dtype=object)

            bdry_vis.write_vtk_file("source-%s.vtu" % nel_factor, [
                ("density", density),
                ("sp_ext", sp_ext),
                ("sp_avg", sp_avg),
                ("bdry_normals", bdry_normals),
                ])

        # }}}

    print(eoc_rec)

    assert eoc_rec.order_estimate() >= qbx_order - 1.5
Esempio n. 55
0
def refine_for_global_qbx(lpot_source, wrangler,
        group_factory, kernel_length_scale=None,
        force_stage2_uniform_refinement_rounds=None,
        scaled_max_curvature_threshold=None,
        debug=None, maxiter=None,
        visualize=None, expansion_disturbance_tolerance=None,
        refiner=None):
    """
    Entry point for calling the refiner.

    :arg lpot_source: An instance of :class:`QBXLayerPotentialSource`.

    :arg wrangler: An instance of :class:`RefinerWrangler`.

    :arg group_factory: An instance of
        :class:`meshmode.mesh.discretization.ElementGroupFactory`. Used for
        discretizing the coarse refined mesh.

    :arg kernel_length_scale: The kernel length scale, or *None* if not
        applicable. All panels are refined to below this size.

    :arg maxiter: The maximum number of refiner iterations.

    :returns: A tuple ``(lpot_source, *conn*)`` where ``lpot_source`` is the
        refined layer potential source, and ``conn`` is a
        :class:`meshmode.discretization.connection.DiscretizationConnection`
        going from the original mesh to the refined mesh.
    """

    if maxiter is None:
        maxiter = 10

    if debug is None:
        # FIXME: Set debug=False by default once everything works.
        debug = True

    if expansion_disturbance_tolerance is None:
        expansion_disturbance_tolerance = 0.025

    if force_stage2_uniform_refinement_rounds is None:
        force_stage2_uniform_refinement_rounds = 0

    # TODO: Stop doing redundant checks by avoiding panels which no longer need
    # refinement.

    from meshmode.mesh.refinement import RefinerWithoutAdjacency
    from meshmode.discretization.connection import (
            ChainedDiscretizationConnection, make_same_mesh_connection)

    if refiner is not None:
        assert refiner.get_current_mesh() == lpot_source.density_discr.mesh
    else:
        # We may be handed a mesh that's already non-conforming, we don't rely
        # on adjacency, and the no-adjacency refiner is faster.
        refiner = RefinerWithoutAdjacency(lpot_source.density_discr.mesh)

    connections = []

    # {{{ first stage refinement

    def visualize_refinement(niter, stage_nr, stage_name, flags):
        if not visualize:
            return

        if stage_nr == 1:
            discr = lpot_source.density_discr
        elif stage_nr == 2:
            discr = lpot_source.stage2_density_discr
        else:
            raise ValueError("unexpected stage number")

        flags = flags.get()
        logger.info("for stage %s: splitting %d/%d stage-%d elements",
                stage_name, np.sum(flags), discr.mesh.nelements, stage_nr)

        from meshmode.discretization.visualization import make_visualizer
        vis = make_visualizer(wrangler.queue, discr, 3)

        assert len(flags) == discr.mesh.nelements

        flags = flags.astype(np.bool)
        nodes_flags = np.zeros(discr.nnodes)
        for grp in discr.groups:
            meg = grp.mesh_el_group
            grp.view(nodes_flags)[
                    flags[meg.element_nr_base:meg.nelements+meg.element_nr_base]] = 1

        nodes_flags = cl.array.to_device(wrangler.queue, nodes_flags)
        vis_data = [
            ("refine_flags", nodes_flags),
            ]

        if 0:
            from pytential import sym, bind
            bdry_normals = bind(discr, sym.normal(discr.ambient_dim))(
                    wrangler.queue).as_vector(dtype=object)
            vis_data.append(("bdry_normals", bdry_normals),)

        vis.write_vtk_file("refinement-%s-%03d.vtu" % (stage_name, niter), vis_data)

    def warn_max_iterations():
        from warnings import warn
        warn(
                "QBX layer potential source refiner did not terminate "
                "after %d iterations (the maximum). "
                "You may pass 'visualize=True' to with_refinement() "
                "to see what area of the geometry is causing trouble. "
                "If the issue is disturbance of expansion disks, you may "
                "pass a slightly increased value (currently: %g) for "
                "_expansion_disturbance_tolerance in with_refinement(). "
                "As a last resort, "
                "you may use Python's warning filtering mechanism to "
                "not treat this warning as an error. "
                "The criteria triggering refinement in each iteration "
                "were: %s. " % (
                    len(violated_criteria),
                    expansion_disturbance_tolerance,
                    ", ".join(
                        "%d: %s" % (i+1, vc_text)
                        for i, vc_text in enumerate(violated_criteria))),
                RefinerNotConvergedWarning)

    violated_criteria = []
    iter_violated_criteria = ["start"]

    niter = 0

    while iter_violated_criteria:
        iter_violated_criteria = []
        niter += 1

        if niter > maxiter:
            warn_max_iterations()
            break

        refine_flags = make_empty_refine_flags(wrangler.queue, lpot_source)

        if kernel_length_scale is not None:
            with ProcessLogger(logger,
                    "checking kernel length scale to panel size ratio"):

                violates_kernel_length_scale = \
                        wrangler.check_element_prop_threshold(
                                element_property=(
                                    lpot_source._coarsest_quad_resolution(
                                        "npanels")),
                                threshold=kernel_length_scale,
                                refine_flags=refine_flags, debug=debug)

                if violates_kernel_length_scale:
                    iter_violated_criteria.append("kernel length scale")
                    visualize_refinement(
                            niter, 1, "kernel-length-scale", refine_flags)

        if scaled_max_curvature_threshold is not None:
            with ProcessLogger(logger,
                    "checking scaled max curvature threshold"):
                from pytential.qbx.utils import to_last_dim_length
                from pytential import sym, bind
                scaled_max_curv = to_last_dim_length(
                        lpot_source.density_discr,
                        bind(lpot_source,
                            sym.ElementwiseMax(
                                sym._scaled_max_curvature(
                                    lpot_source.density_discr.ambient_dim)))
                            (wrangler.queue), "npanels")

                violates_scaled_max_curv = \
                        wrangler.check_element_prop_threshold(
                                element_property=scaled_max_curv,
                                threshold=scaled_max_curvature_threshold,
                                refine_flags=refine_flags, debug=debug)

                if violates_scaled_max_curv:
                    iter_violated_criteria.append("curvature")
                    visualize_refinement(niter, 1, "curvature", refine_flags)

        if not iter_violated_criteria:
            # Only start building trees once the simple length-based criteria
            # are happy.

            # Build tree and auxiliary data.
            # FIXME: The tree should not have to be rebuilt at each iteration.
            tree = wrangler.build_tree(lpot_source)
            peer_lists = wrangler.find_peer_lists(tree)

            has_disturbed_expansions = \
                    wrangler.check_expansion_disks_undisturbed_by_sources(
                            lpot_source, tree, peer_lists,
                            expansion_disturbance_tolerance,
                            refine_flags, debug)
            if has_disturbed_expansions:
                iter_violated_criteria.append("disturbed expansions")
                visualize_refinement(niter, 1, "disturbed-expansions", refine_flags)

            del tree
            del peer_lists

        if iter_violated_criteria:
            violated_criteria.append(" and ".join(iter_violated_criteria))

            conn = wrangler.refine(
                    lpot_source.density_discr, refiner, refine_flags,
                    group_factory, debug)
            connections.append(conn)
            lpot_source = lpot_source.copy(density_discr=conn.to_discr)

        del refine_flags

    # }}}

    # {{{ second stage refinement

    iter_violated_criteria = ["start"]
    niter = 0
    fine_connections = []

    stage2_density_discr = lpot_source.density_discr

    while iter_violated_criteria:
        iter_violated_criteria = []
        niter += 1

        if niter > maxiter:
            warn_max_iterations()
            break

        # Build tree and auxiliary data.
        # FIXME: The tree should not have to be rebuilt at each iteration.
        tree = wrangler.build_tree(lpot_source, use_stage2_discr=True)
        peer_lists = wrangler.find_peer_lists(tree)
        refine_flags = make_empty_refine_flags(
                wrangler.queue, lpot_source, use_stage2_discr=True)

        has_insufficient_quad_res = \
                wrangler.check_sufficient_source_quadrature_resolution(
                        lpot_source, tree, peer_lists, refine_flags, debug)
        if has_insufficient_quad_res:
            iter_violated_criteria.append("insufficient quadrature resolution")
            visualize_refinement(niter, 2, "quad-resolution", refine_flags)

        if iter_violated_criteria:
            violated_criteria.append(" and ".join(iter_violated_criteria))

            conn = wrangler.refine(
                    stage2_density_discr,
                    refiner, refine_flags, group_factory, debug)
            stage2_density_discr = conn.to_discr
            fine_connections.append(conn)
            lpot_source = lpot_source.copy(
                    to_refined_connection=ChainedDiscretizationConnection(
                        fine_connections))

        del tree
        del refine_flags
        del peer_lists

    for round in range(force_stage2_uniform_refinement_rounds):
        conn = wrangler.refine(
                stage2_density_discr,
                refiner,
                np.ones(stage2_density_discr.mesh.nelements, dtype=np.bool),
                group_factory, debug)
        stage2_density_discr = conn.to_discr
        fine_connections.append(conn)
        lpot_source = lpot_source.copy(
                to_refined_connection=ChainedDiscretizationConnection(
                    fine_connections))

    # }}}

    lpot_source = lpot_source.copy(debug=debug, _refined_for_global_qbx=True)

    if len(connections) == 0:
        # FIXME: This is inefficient
        connection = make_same_mesh_connection(
                lpot_source.density_discr,
                lpot_source.density_discr)
    else:
        connection = ChainedDiscretizationConnection(connections)

    return lpot_source, connection
Esempio n. 56
0
def run_int_eq_test(cl_ctx, queue, case, resolution, visualize):
    mesh = case.get_mesh(resolution, case.target_order)
    print("%d elements" % mesh.nelements)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory
    pre_density_discr = Discretization(
            cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(case.target_order))

    source_order = 4*case.target_order

    refiner_extra_kwargs = {}

    qbx_lpot_kwargs = {}
    if case.fmm_backend is None:
        qbx_lpot_kwargs["fmm_order"] = False
    else:
        if hasattr(case, "fmm_tol"):
            from sumpy.expansion.level_to_order import SimpleExpansionOrderFinder
            qbx_lpot_kwargs["fmm_level_to_order"] = SimpleExpansionOrderFinder(
                    case.fmm_tol)

        elif hasattr(case, "fmm_order"):
            qbx_lpot_kwargs["fmm_order"] = case.fmm_order
        else:
            qbx_lpot_kwargs["fmm_order"] = case.qbx_order + 5

    qbx = QBXLayerPotentialSource(
            pre_density_discr,
            fine_order=source_order,
            qbx_order=case.qbx_order,

            _box_extent_norm=getattr(case, "box_extent_norm", None),
            _from_sep_smaller_crit=getattr(case, "from_sep_smaller_crit", None),
            _from_sep_smaller_min_nsources_cumul=30,
            fmm_backend=case.fmm_backend, **qbx_lpot_kwargs)

    if case.use_refinement:
        if case.k != 0 and getattr(case, "refine_on_helmholtz_k", True):
            refiner_extra_kwargs["kernel_length_scale"] = 5/case.k

        if hasattr(case, "scaled_max_curvature_threshold"):
            refiner_extra_kwargs["_scaled_max_curvature_threshold"] = \
                    case.scaled_max_curvature_threshold

        if hasattr(case, "expansion_disturbance_tolerance"):
            refiner_extra_kwargs["_expansion_disturbance_tolerance"] = \
                    case.expansion_disturbance_tolerance

        if hasattr(case, "refinement_maxiter"):
            refiner_extra_kwargs["maxiter"] = case.refinement_maxiter

        #refiner_extra_kwargs["visualize"] = True

        print("%d elements before refinement" % pre_density_discr.mesh.nelements)
        qbx, _ = qbx.with_refinement(**refiner_extra_kwargs)
        print("%d stage-1 elements after refinement"
                % qbx.density_discr.mesh.nelements)
        print("%d stage-2 elements after refinement"
                % qbx.stage2_density_discr.mesh.nelements)
        print("quad stage-2 elements have %d nodes"
                % qbx.quad_stage2_density_discr.groups[0].nunit_nodes)

    density_discr = qbx.density_discr

    if hasattr(case, "visualize_geometry") and case.visualize_geometry:
        bdry_normals = bind(
                density_discr, sym.normal(mesh.ambient_dim)
                )(queue).as_vector(dtype=object)

        bdry_vis = make_visualizer(queue, density_discr, case.target_order)
        bdry_vis.write_vtk_file("geometry.vtu", [
            ("normals", bdry_normals)
            ])

    # {{{ plot geometry

    if 0:
        if mesh.ambient_dim == 2:
            # show geometry, centers, normals
            nodes_h = density_discr.nodes().get(queue=queue)
            pt.plot(nodes_h[0], nodes_h[1], "x-")
            normal = bind(density_discr, sym.normal(2))(queue).as_vector(np.object)
            pt.quiver(nodes_h[0], nodes_h[1],
                    normal[0].get(queue), normal[1].get(queue))
            pt.gca().set_aspect("equal")
            pt.show()

        elif mesh.ambient_dim == 3:
            bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)

            bdry_normals = bind(density_discr, sym.normal(3))(queue)\
                    .as_vector(dtype=object)

            bdry_vis.write_vtk_file("pre-solve-source-%s.vtu" % resolution, [
                ("bdry_normals", bdry_normals),
                ])

        else:
            raise ValueError("invalid mesh dim")

    # }}}

    # {{{ set up operator

    from pytential.symbolic.pde.scalar import (
            DirichletOperator,
            NeumannOperator)

    from sumpy.kernel import LaplaceKernel, HelmholtzKernel
    if case.k:
        knl = HelmholtzKernel(mesh.ambient_dim)
        knl_kwargs = {"k": sym.var("k")}
        concrete_knl_kwargs = {"k": case.k}
    else:
        knl = LaplaceKernel(mesh.ambient_dim)
        knl_kwargs = {}
        concrete_knl_kwargs = {}

    if knl.is_complex_valued:
        dtype = np.complex128
    else:
        dtype = np.float64

    loc_sign = +1 if case.prob_side in [+1, "scat"] else -1

    if case.bc_type == "dirichlet":
        op = DirichletOperator(knl, loc_sign, use_l2_weighting=True,
                kernel_arguments=knl_kwargs)
    elif case.bc_type == "neumann":
        op = NeumannOperator(knl, loc_sign, use_l2_weighting=True,
                 use_improved_operator=False, kernel_arguments=knl_kwargs)
    else:
        assert False

    op_u = op.operator(sym.var("u"))

    # }}}

    # {{{ set up test data

    if case.prob_side == -1:
        test_src_geo_radius = case.outer_radius
        test_tgt_geo_radius = case.inner_radius
    elif case.prob_side == +1:
        test_src_geo_radius = case.inner_radius
        test_tgt_geo_radius = case.outer_radius
    elif case.prob_side == "scat":
        test_src_geo_radius = case.outer_radius
        test_tgt_geo_radius = case.outer_radius
    else:
        raise ValueError("unknown problem_side")

    point_sources = make_circular_point_group(
            mesh.ambient_dim, 10, test_src_geo_radius,
            func=lambda x: x**1.5)
    test_targets = make_circular_point_group(
            mesh.ambient_dim, 20, test_tgt_geo_radius)

    np.random.seed(22)
    source_charges = np.random.randn(point_sources.shape[1])
    source_charges[-1] = -np.sum(source_charges[:-1])
    source_charges = source_charges.astype(dtype)
    assert np.sum(source_charges) < 1e-15

    source_charges_dev = cl.array.to_device(queue, source_charges)

    # }}}

    # {{{ establish BCs

    from pytential.source import PointPotentialSource
    from pytential.target import PointsTarget

    point_source = PointPotentialSource(cl_ctx, point_sources)

    pot_src = sym.IntG(
        # FIXME: qbx_forced_limit--really?
        knl, sym.var("charges"), qbx_forced_limit=None, **knl_kwargs)

    test_direct = bind((point_source, PointsTarget(test_targets)), pot_src)(
            queue, charges=source_charges_dev, **concrete_knl_kwargs)

    if case.bc_type == "dirichlet":
        bc = bind((point_source, density_discr), pot_src)(
                queue, charges=source_charges_dev, **concrete_knl_kwargs)

    elif case.bc_type == "neumann":
        bc = bind(
                (point_source, density_discr),
                sym.normal_derivative(
                    qbx.ambient_dim, pot_src, where=sym.DEFAULT_TARGET)
                )(queue, charges=source_charges_dev, **concrete_knl_kwargs)

    # }}}

    # {{{ solve

    bound_op = bind(qbx, op_u)

    rhs = bind(density_discr, op.prepare_rhs(sym.var("bc")))(queue, bc=bc)

    try:
        from pytential.solve import gmres
        gmres_result = gmres(
                bound_op.scipy_op(queue, "u", dtype, **concrete_knl_kwargs),
                rhs,
                tol=case.gmres_tol,
                progress=True,
                hard_failure=True,
                stall_iterations=50, no_progress_factor=1.05)
    except QBXTargetAssociationFailedException as e:
        bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)

        bdry_vis.write_vtk_file("failed-targets-%s.vtu" % resolution, [
            ("failed_targets", e.failed_target_flags),
            ])
        raise

    print("gmres state:", gmres_result.state)
    weighted_u = gmres_result.solution

    # }}}

    # {{{ build matrix for spectrum check

    if 0:
        from sumpy.tools import build_matrix
        mat = build_matrix(
                bound_op.scipy_op(
                    queue, arg_name="u", dtype=dtype, k=case.k))
        w, v = la.eig(mat)
        if 0:
            pt.imshow(np.log10(1e-20+np.abs(mat)))
            pt.colorbar()
            pt.show()

        #assert abs(s[-1]) < 1e-13, "h
        #assert abs(s[-2]) > 1e-7
        #from pudb import set_trace; set_trace()

    # }}}

    if case.prob_side != "scat":
        # {{{ error check

        points_target = PointsTarget(test_targets)
        bound_tgt_op = bind((qbx, points_target),
                op.representation(sym.var("u")))

        test_via_bdry = bound_tgt_op(queue, u=weighted_u, k=case.k)

        err = test_via_bdry - test_direct

        err = err.get()
        test_direct = test_direct.get()
        test_via_bdry = test_via_bdry.get()

        # {{{ remove effect of net source charge

        if case.k == 0 and case.bc_type == "neumann" and loc_sign == -1:

            # remove constant offset in interior Laplace Neumann error
            tgt_ones = np.ones_like(test_direct)
            tgt_ones = tgt_ones/la.norm(tgt_ones)
            err = err - np.vdot(tgt_ones, err)*tgt_ones

        # }}}

        rel_err_2 = la.norm(err)/la.norm(test_direct)
        rel_err_inf = la.norm(err, np.inf)/la.norm(test_direct, np.inf)

        # }}}

        print("rel_err_2: %g rel_err_inf: %g" % (rel_err_2, rel_err_inf))

    else:
        rel_err_2 = None
        rel_err_inf = None

    # {{{ test gradient

    if case.check_gradient and case.prob_side != "scat":
        bound_grad_op = bind((qbx, points_target),
                op.representation(
                    sym.var("u"),
                    map_potentials=lambda pot: sym.grad(mesh.ambient_dim, pot),
                    qbx_forced_limit=None))

        #print(bound_t_deriv_op.code)

        grad_from_src = bound_grad_op(
                queue, u=weighted_u, **concrete_knl_kwargs)

        grad_ref = (bind(
                (point_source, points_target),
                sym.grad(mesh.ambient_dim, pot_src)
                )(queue, charges=source_charges_dev, **concrete_knl_kwargs)
                )

        grad_err = (grad_from_src - grad_ref)

        rel_grad_err_inf = (
                la.norm(grad_err[0].get(), np.inf)
                / la.norm(grad_ref[0].get(), np.inf))

        print("rel_grad_err_inf: %g" % rel_grad_err_inf)

    # }}}

    # {{{ test tangential derivative

    if case.check_tangential_deriv and case.prob_side != "scat":
        bound_t_deriv_op = bind(qbx,
                op.representation(
                    sym.var("u"),
                    map_potentials=lambda pot: sym.tangential_derivative(2, pot),
                    qbx_forced_limit=loc_sign))

        #print(bound_t_deriv_op.code)

        tang_deriv_from_src = bound_t_deriv_op(
                queue, u=weighted_u, **concrete_knl_kwargs).as_scalar().get()

        tang_deriv_ref = (bind(
                (point_source, density_discr),
                sym.tangential_derivative(2, pot_src)
                )(queue, charges=source_charges_dev, **concrete_knl_kwargs)
                .as_scalar().get())

        if 0:
            pt.plot(tang_deriv_ref.real)
            pt.plot(tang_deriv_from_src.real)
            pt.show()

        td_err = (tang_deriv_from_src - tang_deriv_ref)

        rel_td_err_inf = la.norm(td_err, np.inf)/la.norm(tang_deriv_ref, np.inf)

        print("rel_td_err_inf: %g" % rel_td_err_inf)

    else:
        rel_td_err_inf = None

    # }}}

    # {{{ any-D file plotting

    if visualize:
        bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)

        bdry_normals = bind(density_discr, sym.normal(qbx.ambient_dim))(queue)\
                .as_vector(dtype=object)

        sym_sqrt_j = sym.sqrt_jac_q_weight(density_discr.ambient_dim)
        u = bind(density_discr, sym.var("u")/sym_sqrt_j)(queue, u=weighted_u)

        bdry_vis.write_vtk_file("source-%s.vtu" % resolution, [
            ("u", u),
            ("bc", bc),
            #("bdry_normals", bdry_normals),
            ])

        from sumpy.visualization import make_field_plotter_from_bbox  # noqa
        from meshmode.mesh.processing import find_bounding_box

        vis_grid_spacing = (0.1, 0.1, 0.1)[:qbx.ambient_dim]
        if hasattr(case, "vis_grid_spacing"):
            vis_grid_spacing = case.vis_grid_spacing
        vis_extend_factor = 0.2
        if hasattr(case, "vis_extend_factor"):
            vis_grid_spacing = case.vis_grid_spacing

        fplot = make_field_plotter_from_bbox(
                find_bounding_box(mesh),
                h=vis_grid_spacing,
                extend_factor=vis_extend_factor)

        qbx_tgt_tol = qbx.copy(target_association_tolerance=0.15)
        from pytential.target import PointsTarget

        try:
            solved_pot = bind(
                    (qbx_tgt_tol, PointsTarget(fplot.points)),
                    op.representation(sym.var("u"))
                    )(queue, u=weighted_u, k=case.k)
        except QBXTargetAssociationFailedException as e:
            fplot.write_vtk_file(
                    "failed-targets.vts",
                    [
                        ("failed_targets", e.failed_target_flags.get(queue))
                        ])
            raise

        from sumpy.kernel import LaplaceKernel
        ones_density = density_discr.zeros(queue)
        ones_density.fill(1)
        indicator = bind(
                (qbx_tgt_tol, PointsTarget(fplot.points)),
                -sym.D(LaplaceKernel(density_discr.ambient_dim),
                    sym.var("sigma"),
                    qbx_forced_limit=None))(
                queue, sigma=ones_density).get()

        solved_pot = solved_pot.get()

        true_pot = bind((point_source, PointsTarget(fplot.points)), pot_src)(
                queue, charges=source_charges_dev, **concrete_knl_kwargs).get()

        #fplot.show_scalar_in_mayavi(solved_pot.real, max_val=5)
        if case.prob_side == "scat":
            fplot.write_vtk_file(
                    "potential-%s.vts" % resolution,
                    [
                        ("pot_scattered", solved_pot),
                        ("pot_incoming", -true_pot),
                        ("indicator", indicator),
                        ]
                    )
        else:
            fplot.write_vtk_file(
                    "potential-%s.vts" % resolution,
                    [
                        ("solved_pot", solved_pot),
                        ("true_pot", true_pot),
                        ("indicator", indicator),
                        ]
                    )

    # }}}

    class Result(Record):
        pass

    return Result(
            h_max=qbx.h_max,
            rel_err_2=rel_err_2,
            rel_err_inf=rel_err_inf,
            rel_td_err_inf=rel_td_err_inf,
            gmres_result=gmres_result)
Esempio n. 57
0
def test_off_surface_eval(ctx_getter, use_fmm, do_plot=False):
    logging.basicConfig(level=logging.INFO)

    cl_ctx = ctx_getter()
    queue = cl.CommandQueue(cl_ctx)

    # prevent cache 'splosion
    from sympy.core.cache import clear_cache
    clear_cache()

    nelements = 30
    target_order = 8
    qbx_order = 3
    if use_fmm:
        fmm_order = qbx_order
    else:
        fmm_order = False

    mesh = make_curve_mesh(partial(ellipse, 3),
            np.linspace(0, 1, nelements+1),
            target_order)

    from pytential.qbx import QBXLayerPotentialSource
    from meshmode.discretization import Discretization
    from meshmode.discretization.poly_element import \
            InterpolatoryQuadratureSimplexGroupFactory

    pre_density_discr = Discretization(
            cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
    qbx, _ = QBXLayerPotentialSource(
            pre_density_discr,
            4*target_order,
            qbx_order,
            fmm_order=fmm_order,
            ).with_refinement()

    density_discr = qbx.density_discr

    from sumpy.kernel import LaplaceKernel
    op = sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=-2)

    sigma = density_discr.zeros(queue) + 1

    fplot = FieldPlotter(np.zeros(2), extent=0.54, npoints=30)
    from pytential.target import PointsTarget
    fld_in_vol = bind(
            (qbx, PointsTarget(fplot.points)),
            op)(queue, sigma=sigma)

    err = cl.clmath.fabs(fld_in_vol - (-1))

    linf_err = cl.array.max(err).get()
    print("l_inf error:", linf_err)

    if do_plot:
        fplot.show_scalar_in_matplotlib(fld_in_vol.get())
        import matplotlib.pyplot as pt
        pt.colorbar()
        pt.show()

    assert linf_err < 1e-3
Esempio n. 58
0
def main():
    logging.basicConfig(level=logging.INFO)

    nelements = 60
    qbx_order = 3
    k_fac = 4
    k0 = 3*k_fac
    k1 = 2.9*k_fac
    mesh_order = 10
    bdry_quad_order = mesh_order
    bdry_ovsmp_quad_order = bdry_quad_order * 4
    fmm_order = qbx_order * 2

    cl_ctx = cl.create_some_context()
    queue = cl.CommandQueue(cl_ctx)

    from meshmode.mesh.generation import ellipse, make_curve_mesh
    from functools import partial
    mesh = make_curve_mesh(
            partial(ellipse, 3),
            np.linspace(0, 1, nelements+1),
            mesh_order)

    density_discr = Discretization(
            cl_ctx, mesh,
            InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))

    logger.info("%d elements" % mesh.nelements)

    # from meshmode.discretization.visualization import make_visualizer
    # bdry_vis = make_visualizer(queue, density_discr, 20)

    # {{{ solve bvp

    from sumpy.kernel import HelmholtzKernel
    kernel = HelmholtzKernel(2)

    beta = 2.5*k_fac
    K0 = np.sqrt(k0**2-beta**2)
    K1 = np.sqrt(k1**2-beta**2)

    from pytential.symbolic.pde.scalar import DielectricSDRep2DBoundaryOperator
    pde_op = DielectricSDRep2DBoundaryOperator(
            mode='tm',
            k_vacuum=1,
            interfaces=((0, 1, sym.DEFAULT_SOURCE),),
            domain_k_exprs=(k0, k1),
            beta=beta)

    op_unknown_sym = pde_op.make_unknown("unknown")

    representation0_sym = pde_op.representation(op_unknown_sym, 0)
    representation1_sym = pde_op.representation(op_unknown_sym, 1)

    from pytential.qbx import QBXLayerPotentialSource
    qbx = QBXLayerPotentialSource(
            density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
            fmm_order=fmm_order
            )

    bound_pde_op = bind(qbx, pde_op.operator(op_unknown_sym))

    # in inner domain
    sources_1 = make_obj_array(list(np.array([
        [-1.5, 0.5]
        ]).T.copy()))
    strengths_1 = np.array([1])

    from sumpy.p2p import P2P
    pot_p2p = P2P(cl_ctx, [kernel], exclude_self=False)

    _, (Einc,) = pot_p2p(queue, density_discr.nodes(), sources_1, [strengths_1],
                    out_host=False, k=K0)

    sqrt_w = bind(density_discr, sym.sqrt_jac_q_weight())(queue)

    bvp_rhs = np.zeros(len(pde_op.bcs), dtype=np.object)
    for i_bc, terms in enumerate(pde_op.bcs):
        for term in terms:
            assert term.i_interface == 0
            assert term.field_kind == pde_op.field_kind_e

            if term.direction == pde_op.dir_none:
                bvp_rhs[i_bc] += (
                        term.coeff_outer * (-Einc)
                        )
            elif term.direction == pde_op.dir_normal:
                # no jump in normal derivative
                bvp_rhs[i_bc] += 0*Einc
            else:
                raise NotImplementedError("direction spec in RHS")

        bvp_rhs[i_bc] *= sqrt_w

    from pytential.solve import gmres
    gmres_result = gmres(
            bound_pde_op.scipy_op(queue, "unknown", dtype=np.complex128,
                domains=[sym.DEFAULT_TARGET]*2, K0=K0, K1=K1),
            bvp_rhs, tol=1e-6, progress=True,
            hard_failure=True, stall_iterations=0)

    # }}}

    unknown = gmres_result.solution

    # {{{ visualize

    from pytential.qbx import QBXLayerPotentialSource
    lap_qbx = QBXLayerPotentialSource(
            density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
            fmm_order=qbx_order
            )

    from sumpy.visualization import FieldPlotter
    fplot = FieldPlotter(np.zeros(2), extent=5, npoints=300)
    from pytential.target import PointsTarget
    fld0 = bind(
            (qbx, PointsTarget(fplot.points)),
            representation0_sym)(queue, unknown=unknown, K0=K0).get()
    fld1 = bind(
            (qbx, PointsTarget(fplot.points)),
            representation1_sym)(queue, unknown=unknown, K1=K1).get()
    ones = cl.array.empty(queue, density_discr.nnodes, np.float64)
    dom1_indicator = -bind(
            (lap_qbx, PointsTarget(fplot.points)),
            sym.D(0, sym.var("sigma")))(
                    queue, sigma=ones.fill(1)).get()
    _, (fld_inc_vol,) = pot_p2p(queue, fplot.points, sources_1, [strengths_1],
                    out_host=True, k=K0)

    #fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
    fplot.write_vtk_file(
            "potential.vts",
            [
                ("fld0", fld0),
                ("fld1", fld1),
                ("fld_inc_vol", fld_inc_vol),
                ("fld_total", (
                    (fld_inc_vol + fld0)*(1-dom1_indicator)
                    +
                    fld1*dom1_indicator
                    )),
                ("dom1_indicator", dom1_indicator),
                ]
            )
Esempio n. 59
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def test_sanity_balls(ctx_getter, src_file, dim, mesh_order,
        visualize=False):
    pytest.importorskip("pytential")

    logging.basicConfig(level=logging.INFO)

    ctx = ctx_getter()
    queue = cl.CommandQueue(ctx)

    from pytools.convergence import EOCRecorder
    vol_eoc_rec = EOCRecorder()
    surf_eoc_rec = EOCRecorder()

    # overkill
    quad_order = mesh_order

    from pytential import bind, sym

    for h in [0.2, 0.14, 0.1]:
        from meshmode.mesh.io import generate_gmsh, FileSource
        mesh = generate_gmsh(
                FileSource(src_file), dim, order=mesh_order,
                other_options=["-string", "Mesh.CharacteristicLengthMax = %g;" % h],
                force_ambient_dim=dim)

        logger.info("%d elements" % mesh.nelements)

        # {{{ discretizations and connections

        from meshmode.discretization import Discretization
        from meshmode.discretization.poly_element import \
                InterpolatoryQuadratureSimplexGroupFactory
        vol_discr = Discretization(ctx, mesh,
                InterpolatoryQuadratureSimplexGroupFactory(quad_order))

        from meshmode.discretization.connection import make_boundary_restriction
        bdry_mesh, bdry_discr, bdry_connection = make_boundary_restriction(
                queue, vol_discr,
                InterpolatoryQuadratureSimplexGroupFactory(quad_order))

        # }}}

        # {{{ visualizers

        from meshmode.discretization.visualization import make_visualizer
        vol_vis = make_visualizer(queue, vol_discr, 20)
        bdry_vis = make_visualizer(queue, bdry_discr, 20)

        # }}}

        from math import gamma
        true_surf = 2*np.pi**(dim/2)/gamma(dim/2)
        true_vol = true_surf/dim

        vol_x = vol_discr.nodes().with_queue(queue)

        vol_one = vol_x[0].copy()
        vol_one.fill(1)
        from pytential import norm, integral  # noqa

        comp_vol = integral(vol_discr, queue, vol_one)
        rel_vol_err = abs(true_vol - comp_vol) / true_vol
        vol_eoc_rec.add_data_point(h, rel_vol_err)
        print("VOL", true_vol, comp_vol)

        bdry_x = bdry_discr.nodes().with_queue(queue)

        bdry_one_exact = bdry_x[0].copy()
        bdry_one_exact.fill(1)

        bdry_one = bdry_connection(queue, vol_one).with_queue(queue)
        intp_err = norm(bdry_discr, queue, bdry_one-bdry_one_exact)
        assert intp_err < 1e-14

        comp_surf = integral(bdry_discr, queue, bdry_one)
        rel_surf_err = abs(true_surf - comp_surf) / true_surf
        surf_eoc_rec.add_data_point(h, rel_surf_err)
        print("SURF", true_surf, comp_surf)

        if visualize:
            vol_vis.write_vtk_file("volume-h=%g.vtu" % h, [
                ("f", vol_one),
                ("area_el", bind(vol_discr, sym.area_element())(queue)),
                ])
            bdry_vis.write_vtk_file("boundary-h=%g.vtu" % h, [("f", bdry_one)])

        # {{{ check normals point outward

        normal_outward_check = bind(bdry_discr,
                sym.normal() | sym.Nodes(),
                )(queue).as_scalar() > 0

        assert normal_outward_check.get().all(), normal_outward_check.get()

        # }}}

    print("---------------------------------")
    print("VOLUME")
    print("---------------------------------")
    print(vol_eoc_rec)
    assert vol_eoc_rec.order_estimate() >= mesh_order

    print("---------------------------------")
    print("SURFACE")
    print("---------------------------------")
    print(surf_eoc_rec)
    assert surf_eoc_rec.order_estimate() >= mesh_order