Exemplo n.º 1
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    def sym_operator(self):
        u = sym.var("u")

        # boundary conditions -------------------------------------------------
        bc_in = self.inflow_u

        all_faces_dd = sym.DOFDesc(sym.FACE_RESTR_ALL, self.quad_tag)
        boundary_dd = sym.DOFDesc(sym.BTAG_ALL, self.quad_tag)

        def flux(pair):
            return sym.interp(pair.dd, all_faces_dd)(
                    self.flux(pair))

        quad_dd = sym.DOFDesc("vol", self.quad_tag)

        to_quad = sym.interp("vol", quad_dd)

        stiff_t = sym.stiffness_t(self.ambient_dim, quad_dd, "vol")
        quad_v = to_quad(self.v)
        quad_u = to_quad(u)

        return sym.InverseMassOperator()(
                (stiff_t[0](quad_u * quad_v[0]) + stiff_t[1](quad_u * quad_v[1]))
                - sym.FaceMassOperator(all_faces_dd, "vol")(
                    flux(sym.int_tpair(u, self.quad_tag))
                    + flux(sym.bv_tpair(boundary_dd, u, bc_in))

                    # FIXME: Add back support for inflow/outflow tags
                    #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                    #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
                ))
Exemplo n.º 2
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    def sym_operator(self):
        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, face_dd)(self.flux(pair))

        face_dd = sym.DOFDesc(sym.FACE_RESTR_ALL, self.quad_tag)
        boundary_dd = sym.DOFDesc(sym.BTAG_ALL, self.quad_tag)
        quad_dd = sym.DOFDesc(sym.DTAG_VOLUME_ALL, self.quad_tag)

        to_quad = sym.project(sym.DD_VOLUME, quad_dd)
        stiff_t_op = sym.stiffness_t(self.ambient_dim,
                dd_in=quad_dd, dd_out=sym.DD_VOLUME)

        quad_v = to_quad(self.v)
        quad_u = to_quad(u)

        return sym.InverseMassOperator()(
                sum(stiff_t_op[n](quad_u * quad_v[n])
                    for n in range(self.ambient_dim))
                - sym.FaceMassOperator(face_dd, sym.DD_VOLUME)(
                    flux(sym.int_tpair(u, self.quad_tag))
                    + flux(sym.bv_tpair(boundary_dd, u, self.inflow_u))

                    # FIXME: Add back support for inflow/outflow tags
                    #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                    #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
                ))
Exemplo n.º 3
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Arquivo: em.py Projeto: majosm/grudge
    def sym_operator(self, w=None):
        """The full operator template - the high level description of
        the Maxwell operator.

        Combines the relevant operator templates for spatial
        derivatives, flux, boundary conditions etc.
        """
        from grudge.tools import count_subset
        w = sym.make_sym_array("w", count_subset(self.get_eh_subset()))

        elec_components = count_subset(self.get_eh_subset()[0:3])
        mag_components = count_subset(self.get_eh_subset()[3:6])

        if self.fixed_material:
            # need to check this
            material_divisor = ([self.epsilon] * elec_components +
                                [self.mu] * mag_components)

        tags_and_bcs = [
            (self.pec_tag, self.pec_bc(w)),
            (self.pmc_tag, self.pmc_bc(w)),
            (self.absorb_tag, self.absorbing_bc(w)),
            (self.incident_tag, self.incident_bc(w)),
        ]

        def flux(pair):
            return sym.project(pair.dd, "all_faces")(self.flux(pair))

        return (-self.local_derivatives(w) - sym.InverseMassOperator()
                (sym.FaceMassOperator()(flux(sym.int_tpair(w)) + sum(
                    flux(sym.bv_tpair(tag, w, bc))
                    for tag, bc in tags_and_bcs)))) / material_divisor
Exemplo n.º 4
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    def sym_operator(self):
        from grudge.dof_desc import DOFDesc, DD_VOLUME, DTAG_VOLUME_ALL
        from meshmode.discretization.connection import FACE_RESTR_ALL

        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, face_dd)(self.flux(pair))

        face_dd = DOFDesc(FACE_RESTR_ALL, self.quad_tag)
        quad_dd = DOFDesc(DTAG_VOLUME_ALL, self.quad_tag)

        to_quad = sym.project(DD_VOLUME, quad_dd)
        stiff_t_op = sym.stiffness_t(self.ambient_dim,
                                     dd_in=quad_dd,
                                     dd_out=DD_VOLUME)

        quad_v = to_quad(self.v)
        quad_u = to_quad(u)

        return sym.InverseMassOperator()(
            sum(stiff_t_op[n](quad_u * quad_v[n])
                for n in range(self.ambient_dim)) -
            sym.FaceMassOperator(face_dd, DD_VOLUME)
            (flux(sym.int_tpair(u, self.quad_tag))))
Exemplo n.º 5
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    def sym_operator(self):
        from grudge.dof_desc import DOFDesc, DD_VOLUME, DTAG_VOLUME_ALL
        from meshmode.mesh import BTAG_ALL
        from meshmode.discretization.connection import FACE_RESTR_ALL

        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, face_dd)(self.flux(pair))

        face_dd = DOFDesc(FACE_RESTR_ALL, self.quad_tag)
        boundary_dd = DOFDesc(BTAG_ALL, self.quad_tag)
        quad_dd = DOFDesc(DTAG_VOLUME_ALL, self.quad_tag)

        to_quad = sym.project(DD_VOLUME, quad_dd)
        stiff_t_op = sym.stiffness_t(self.ambient_dim,
                                     dd_in=quad_dd,
                                     dd_out=DD_VOLUME)

        quad_v = to_quad(self.v)
        quad_u = to_quad(u)

        return sym.InverseMassOperator()(
            sum(stiff_t_op[n](quad_u * quad_v[n])
                for n in range(self.ambient_dim)) -
            sym.FaceMassOperator(face_dd, DD_VOLUME)(
                flux(sym.int_tpair(u, self.quad_tag)) +
                flux(sym.bv_tpair(boundary_dd, u, self.inflow_u))

                # FIXME: Add back support for inflow/outflow tags
                #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
            ))
Exemplo n.º 6
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    def sym_operator(self):
        d = self.ambient_dim

        w = sym.make_sym_array("w", d + 1)
        u = w[0]
        v = w[1:]

        # boundary conditions -------------------------------------------------

        # dirichlet BCs -------------------------------------------------------
        dir_u = sym.cse(sym.interp("vol", self.dirichlet_tag)(u))
        dir_v = sym.cse(sym.interp("vol", self.dirichlet_tag)(v))
        if self.dirichlet_bc_f:
            # FIXME
            from warnings import warn
            warn("Inhomogeneous Dirichlet conditions on the wave equation "
                 "are still having issues.")

            dir_g = sym.Field("dir_bc_u")
            dir_bc = join_fields(2 * dir_g - dir_u, dir_v)
        else:
            dir_bc = join_fields(-dir_u, dir_v)

        dir_bc = sym.cse(dir_bc, "dir_bc")

        # neumann BCs ---------------------------------------------------------
        neu_u = sym.cse(sym.interp("vol", self.neumann_tag)(u))
        neu_v = sym.cse(sym.interp("vol", self.neumann_tag)(v))
        neu_bc = sym.cse(join_fields(neu_u, -neu_v), "neu_bc")

        # radiation BCs -------------------------------------------------------
        rad_normal = sym.normal(self.radiation_tag, d)

        rad_u = sym.cse(sym.interp("vol", self.radiation_tag)(u))
        rad_v = sym.cse(sym.interp("vol", self.radiation_tag)(v))

        rad_bc = sym.cse(
            join_fields(
                0.5 * (rad_u - self.sign * np.dot(rad_normal, rad_v)), 0.5 *
                rad_normal * (np.dot(rad_normal, rad_v) - self.sign * rad_u)),
            "rad_bc")

        # entire operator -----------------------------------------------------
        def flux(pair):
            return sym.interp(pair.dd, "all_faces")(self.flux(pair))

        result = sym.InverseMassOperator()(
            join_fields(-self.c *
                        np.dot(sym.stiffness_t(self.ambient_dim), v), -self.c *
                        (sym.stiffness_t(self.ambient_dim) * u)) -
            sym.FaceMassOperator()
            (flux(sym.int_tpair(w)) +
             flux(sym.bv_tpair(self.dirichlet_tag, w, dir_bc)) +
             flux(sym.bv_tpair(self.neumann_tag, w, neu_bc)) +
             flux(sym.bv_tpair(self.radiation_tag, w, rad_bc))))

        result[0] += self.source_f

        return result
Exemplo n.º 7
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def get_strong_wave_op_with_discr_direct(cl_ctx, dims=2, order=4):
    from meshmode.mesh.generation import generate_regular_rect_mesh
    mesh = generate_regular_rect_mesh(a=(-0.5, ) * dims,
                                      b=(0.5, ) * dims,
                                      n=(16, ) * dims)

    logger.debug("%d elements", mesh.nelements)

    discr = DGDiscretizationWithBoundaries(cl_ctx, mesh, order=order)

    source_center = np.array([0.1, 0.22, 0.33])[:dims]
    source_width = 0.05
    source_omega = 3

    sym_x = sym.nodes(mesh.dim)
    sym_source_center_dist = sym_x - source_center
    sym_t = sym.ScalarVariable("t")

    from meshmode.mesh import BTAG_ALL

    c = -0.1
    sign = -1

    w = sym.make_sym_array("w", dims + 1)
    u = w[0]
    v = w[1:]

    source_f = (
        sym.sin(source_omega * sym_t) *
        sym.exp(-np.dot(sym_source_center_dist, sym_source_center_dist) /
                source_width**2))

    rad_normal = sym.normal(BTAG_ALL, dims)

    rad_u = sym.cse(sym.interp("vol", BTAG_ALL)(u))
    rad_v = sym.cse(sym.interp("vol", BTAG_ALL)(v))

    rad_bc = sym.cse(
        sym.join_fields(
            0.5 * (rad_u - sign * np.dot(rad_normal, rad_v)),
            0.5 * rad_normal * (np.dot(rad_normal, rad_v) - sign * rad_u)),
        "rad_bc")

    sym_operator = (
        -sym.join_fields(-c * np.dot(sym.nabla(dims), v) - source_f, -c *
                         (sym.nabla(dims) * u)) + sym.InverseMassOperator()(
                             sym.FaceMassOperator()
                             (dg_flux(c, sym.int_tpair(w)) +
                              dg_flux(c, sym.bv_tpair(BTAG_ALL, w, rad_bc)))))

    return (sym_operator, discr)
Exemplo n.º 8
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    def sym_operator(self):
        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, "all_faces")(self.flux(pair))

        return (-self.v.dot(
            sym.nabla(self.ambient_dim) * u
        ) + sym.InverseMassOperator()(
            sym.FaceMassOperator()(
                flux(sym.int_tpair(u)) +
                flux(sym.bv_tpair(sym.BTAG_ALL, u, self.inflow_u))

                # FIXME: Add back support for inflow/outflow tags
                #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
            )))
Exemplo n.º 9
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    def sym_operator(self):
        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, "all_faces")(self.flux(pair))

        bc_in = self.inflow_u
        # bc_out = sym.project(sym.DD_VOLUME, self.outflow_tag)(u)

        return sym.InverseMassOperator()(
            np.dot(self.v,
                   sym.stiffness_t(self.ambient_dim) * u) -
            sym.FaceMassOperator()(
                flux(sym.int_tpair(u)) +
                flux(sym.bv_tpair(sym.BTAG_ALL, u, bc_in))

                # FIXME: Add back support for inflow/outflow tags
                #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
            ))
Exemplo n.º 10
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    def sym_operator(self):
        u = sym.var("u")

        # boundary conditions -------------------------------------------------
        bc_in = self.inflow_u
        # bc_out = sym.interp("vol", self.outflow_tag)(u)

        def flux(pair):
            return sym.interp(pair.dd, "all_faces")(
                    self.flux(pair))

        return sym.InverseMassOperator()(
                np.dot(
                    self.v, sym.stiffness_t(self.ambient_dim)*u)
                - sym.FaceMassOperator()(
                    flux(sym.int_tpair(u))
                    + flux(sym.bv_tpair(sym.BTAG_ALL, u, bc_in))

                    # FIXME: Add back support for inflow/outflow tags
                    #+ flux(sym.bv_tpair(self.inflow_tag, u, bc_in))
                    #+ flux(sym.bv_tpair(self.outflow_tag, u, bc_out))
                    ))
Exemplo n.º 11
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    def sym_operator(self):
        u = sym.var("u")

        def flux(pair):
            return sym.project(pair.dd, face_dd)(self.flux(pair))

        face_dd = sym.DOFDesc(sym.FACE_RESTR_ALL, self.quad_tag)
        quad_dd = sym.DOFDesc(sym.DTAG_VOLUME_ALL, self.quad_tag)

        to_quad = sym.project(sym.DD_VOLUME, quad_dd)
        stiff_t_op = sym.stiffness_t(self.ambient_dim,
                                     dd_in=quad_dd,
                                     dd_out=sym.DD_VOLUME)

        quad_v = to_quad(self.v)
        quad_u = to_quad(u)

        return sym.InverseMassOperator()(
            sum(stiff_t_op[n](quad_u * quad_v[n])
                for n in range(self.ambient_dim)) -
            sym.FaceMassOperator(face_dd, sym.DD_VOLUME)
            (flux(sym.int_tpair(u, self.quad_tag))))
Exemplo n.º 12
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def test_surface_divergence_theorem(actx_factory, mesh_name, visualize=False):
    r"""Check the surface divergence theorem.

        .. math::

            \int_Sigma \phi \nabla_i f_i =
            \int_\Sigma \nabla_i \phi f_i +
            \int_\Sigma \kappa \phi f_i n_i +
            \int_{\partial \Sigma} \phi f_i m_i

        where :math:`n_i` is the surface normal and :class:`m_i` is the
        face normal (which should be orthogonal to both the surface normal
        and the face tangent).
    """
    actx = actx_factory()

    # {{{ cases

    if mesh_name == "2-1-ellipse":
        from mesh_data import EllipseMeshBuilder
        builder = EllipseMeshBuilder(radius=3.1, aspect_ratio=2.0)
    elif mesh_name == "spheroid":
        from mesh_data import SpheroidMeshBuilder
        builder = SpheroidMeshBuilder()
    elif mesh_name == "circle":
        from mesh_data import EllipseMeshBuilder
        builder = EllipseMeshBuilder(radius=1.0, aspect_ratio=1.0)
    elif mesh_name == "starfish":
        from mesh_data import StarfishMeshBuilder
        builder = StarfishMeshBuilder()
    elif mesh_name == "sphere":
        from mesh_data import SphereMeshBuilder
        builder = SphereMeshBuilder(radius=1.0, mesh_order=16)
    else:
        raise ValueError("unknown mesh name: %s" % mesh_name)

    # }}}

    # {{{ convergene

    def f(x):
        return flat_obj_array(
            sym.sin(3 * x[1]) + sym.cos(3 * x[0]) + 1.0,
            sym.sin(2 * x[0]) + sym.cos(x[1]),
            3.0 * sym.cos(x[0] / 2) + sym.cos(x[1]),
        )[:ambient_dim]

    from pytools.convergence import EOCRecorder
    eoc_global = EOCRecorder()
    eoc_local = EOCRecorder()

    theta = np.pi / 3.33
    ambient_dim = builder.ambient_dim
    if ambient_dim == 2:
        mesh_rotation = np.array([
            [np.cos(theta), -np.sin(theta)],
            [np.sin(theta), np.cos(theta)],
        ])
    else:
        mesh_rotation = np.array([
            [1.0, 0.0, 0.0],
            [0.0, np.cos(theta), -np.sin(theta)],
            [0.0, np.sin(theta), np.cos(theta)],
        ])

    mesh_offset = np.array([0.33, -0.21, 0.0])[:ambient_dim]

    for i, resolution in enumerate(builder.resolutions):
        from meshmode.mesh.processing import affine_map
        from meshmode.discretization.connection import FACE_RESTR_ALL

        mesh = builder.get_mesh(resolution, builder.mesh_order)
        mesh = affine_map(mesh, A=mesh_rotation, b=mesh_offset)

        from meshmode.discretization.poly_element import \
                QuadratureSimplexGroupFactory
        discr = DiscretizationCollection(actx,
                                         mesh,
                                         order=builder.order,
                                         discr_tag_to_group_factory={
                                             "product":
                                             QuadratureSimplexGroupFactory(
                                                 2 * builder.order)
                                         })

        volume = discr.discr_from_dd(dof_desc.DD_VOLUME)
        logger.info("ndofs:     %d", volume.ndofs)
        logger.info("nelements: %d", volume.mesh.nelements)

        dd = dof_desc.DD_VOLUME
        dq = dd.with_discr_tag("product")
        df = dof_desc.as_dofdesc(FACE_RESTR_ALL)
        ambient_dim = discr.ambient_dim
        dim = discr.dim

        # variables
        sym_f = f(sym.nodes(ambient_dim, dd=dd))
        sym_f_quad = f(sym.nodes(ambient_dim, dd=dq))
        sym_kappa = sym.summed_curvature(ambient_dim, dim=dim, dd=dq)
        sym_normal = sym.surface_normal(ambient_dim, dim=dim,
                                        dd=dq).as_vector()

        sym_face_normal = sym.normal(df, ambient_dim, dim=dim - 1)
        sym_face_f = sym.project(dd, df)(sym_f)

        # operators
        sym_stiff = sum(
            sym.StiffnessOperator(d)(f) for d, f in enumerate(sym_f))
        sym_stiff_t = sum(
            sym.StiffnessTOperator(d)(f) for d, f in enumerate(sym_f))
        sym_k = sym.MassOperator(dq,
                                 dd)(sym_kappa * sym_f_quad.dot(sym_normal))
        sym_flux = sym.FaceMassOperator()(sym_face_f.dot(sym_face_normal))

        # sum everything up
        sym_op_global = sym.NodalSum(dd)(sym_stiff - (sym_stiff_t + sym_k))
        sym_op_local = sym.ElementwiseSumOperator(dd)(sym_stiff -
                                                      (sym_stiff_t + sym_k +
                                                       sym_flux))

        # evaluate
        op_global = bind(discr, sym_op_global)(actx)
        op_local = bind(discr, sym_op_local)(actx)

        err_global = abs(op_global)
        err_local = bind(discr, sym.norm(np.inf, sym.var("x")))(actx,
                                                                x=op_local)
        logger.info("errors: global %.5e local %.5e", err_global, err_local)

        # compute max element size
        h_max = bind(
            discr,
            sym.h_max_from_volume(discr.ambient_dim, dim=discr.dim,
                                  dd=dd))(actx)
        eoc_global.add_data_point(h_max, err_global)
        eoc_local.add_data_point(h_max, err_local)

        if visualize:
            from grudge.shortcuts import make_visualizer
            vis = make_visualizer(discr, vis_order=builder.order)

            filename = f"surface_divergence_theorem_{mesh_name}_{i:04d}.vtu"
            vis.write_vtk_file(filename, [("r", actx.np.log10(op_local))],
                               overwrite=True)

    # }}}

    order = min(builder.order, builder.mesh_order) - 0.5
    logger.info("\n%s", str(eoc_global))
    logger.info("\n%s", str(eoc_local))

    assert eoc_global.max_error() < 1.0e-12 \
            or eoc_global.order_estimate() > order - 0.5

    assert eoc_local.max_error() < 1.0e-12 \
            or eoc_local.order_estimate() > order - 0.5
Exemplo n.º 13
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def _bound_face_mass(dcoll, dd):
    u = sym.Variable("u", dd=dd)
    return bind(dcoll, sym.FaceMassOperator(dd_in=dd)(u), local_only=True)