Пример #1
0
        def p2p(kernels):
            if any(knl.is_complex_valued for knl in kernels):
                value_dtype = self.complex_dtype
            else:
                value_dtype = self.real_dtype

            from sumpy.p2p import P2P
            return P2P(actx.context,
                       kernels,
                       exclude_self=False,
                       value_dtypes=value_dtype)
Пример #2
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    def get_p2p(self, kernels):
        # needs to be separate method for caching

        from pytools import any
        if any(knl.is_complex_valued for knl in kernels):
            value_dtype = self.density_discr.complex_dtype
        else:
            value_dtype = self.density_discr.real_dtype

        from sumpy.p2p import P2P
        p2p = P2P(self.cl_context,
                  kernels, exclude_self=False, value_dtypes=value_dtype)

        return p2p
Пример #3
0
def test_p2p(ctx_factory, exclude_self):
    ctx = ctx_factory()
    queue = cl.CommandQueue(ctx)

    dimensions = 3
    n = 5000

    from sumpy.p2p import P2P
    lknl = LaplaceKernel(dimensions)
    knl = P2P(ctx, [lknl, AxisTargetDerivative(0, lknl)],
              exclude_self=exclude_self)

    targets = np.random.rand(dimensions, n)
    sources = targets if exclude_self else np.random.rand(dimensions, n)

    strengths = np.ones(n, dtype=np.float64)

    extra_kwargs = {}

    if exclude_self:
        extra_kwargs["target_to_source"] = np.arange(n, dtype=np.int32)

    evt, (potential, x_derivative) = knl(queue,
                                         targets,
                                         sources, [strengths],
                                         out_host=True,
                                         **extra_kwargs)

    potential_ref = np.empty_like(potential)

    targets = targets.T
    sources = sources.T
    for itarg in range(n):

        with np.errstate(divide="ignore"):
            invdists = np.sum((targets[itarg] - sources)**2, axis=-1)**-0.5

        if exclude_self:
            assert np.isinf(invdists[itarg])
            invdists[itarg] = 0

        potential_ref[itarg] = np.sum(strengths * invdists)

    potential_ref *= 1 / (4 * np.pi)

    rel_err = la.norm(potential - potential_ref) / la.norm(potential_ref)
    print(rel_err)
    assert rel_err < 1e-3
Пример #4
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def get_true_sol(fspace, kappa, cl_ctx, queue):
    """
    Get the ufl expression for the true solution (3D)
    or a function with the evaluated solution (2D)
    """
    mesh_dim = fspace.mesh().geometric_dimension()
    if mesh_dim == 3:
        spatial_coord = SpatialCoordinate(fspace.mesh())
        x, y, z = spatial_coord  # pylint: disable=C0103
        norm = sqrt(x**2 + y**2 + z**2)
        return Constant(1j / (4 * pi)) / norm * exp(1j * kappa * norm)

    if mesh_dim == 2:
        # Evaluate true-sol using sumpy
        from sumpy.p2p import P2P
        from sumpy.kernel import HelmholtzKernel
        # https://github.com/inducer/sumpy/blob/900745184d2618bc27a64c847f247e01c2b90b02/examples/curve-pot.py#L87-L88
        p2p = P2P(cl_ctx, [HelmholtzKernel(dim=2)],
                  exclude_self=False,
                  value_dtypes=np.complex128)
        # source is just (0, 0)
        sources = np.array([[0.0], [0.0]])
        strengths = np.array([[1.0], [1.0]])
        # targets are everywhere
        targets = np.array([
            Function(fspace).interpolate(x_i).dat.data
            for x_i in SpatialCoordinate(fspace.mesh())
        ])
        evt, (true_sol_arr, ) = p2p(queue,
                                    targets,
                                    sources,
                                    strengths,
                                    k=kappa)
        true_sol = Function(fspace)
        true_sol.dat.data[:] = true_sol_arr[:]
        return true_sol
    raise ValueError("Only meshes of dimension 2, 3 supported")
Пример #5
0
 def get_p2p(self):
     from sumpy.p2p import P2P
     return P2P(self.cl_context, [self.kernel], exclude_self=False)
Пример #6
0
def test_translations(ctx_factory, knl, local_expn_class, mpole_expn_class):
    logging.basicConfig(level=logging.INFO)

    from sympy.core.cache import clear_cache
    clear_cache()

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

    np.random.seed(17)

    res = 20
    nsources = 15

    out_kernels = [knl]

    extra_kwargs = {}
    if isinstance(knl, HelmholtzKernel):
        extra_kwargs["k"] = 0.05
    if isinstance(knl, StokesletKernel):
        extra_kwargs["mu"] = 0.05

    # Just to make sure things also work away from the origin
    origin = np.array([2, 1, 0][:knl.dim], np.float64)
    sources = (0.7 *
               (-0.5 + np.random.rand(knl.dim, nsources).astype(np.float64)) +
               origin[:, np.newaxis])
    strengths = np.ones(nsources, dtype=np.float64) * (1 / nsources)

    pconv_verifier_p2m2p = PConvergenceVerifier()
    pconv_verifier_p2m2m2p = PConvergenceVerifier()
    pconv_verifier_p2m2m2l2p = PConvergenceVerifier()
    pconv_verifier_full = PConvergenceVerifier()

    from sumpy.visualization import FieldPlotter

    eval_offset = np.array([5.5, 0.0, 0][:knl.dim])

    centers = (
        np.array(
            [
                # box 0: particles, first mpole here
                [0, 0, 0][:knl.dim],

                # box 1: second mpole here
                np.array([-0.2, 0.1, 0][:knl.dim], np.float64),

                # box 2: first local here
                eval_offset + np.array([0.3, -0.2, 0][:knl.dim], np.float64),

                # box 3: second local and eval here
                eval_offset
            ],
            dtype=np.float64) + origin).T.copy()

    del eval_offset

    from sumpy.expansion import VolumeTaylorExpansionBase

    if isinstance(knl, HelmholtzKernel) and \
           issubclass(local_expn_class, VolumeTaylorExpansionBase):
        # FIXME: Embarrassing--but we run out of memory for higher orders.
        orders = [2, 3]
    else:
        orders = [2, 3, 4]
    nboxes = centers.shape[-1]

    def eval_at(e2p, source_box_nr, rscale):
        e2p_target_boxes = np.array([source_box_nr], dtype=np.int32)

        # These are indexed by global box numbers.
        e2p_box_target_starts = np.array([0, 0, 0, 0], dtype=np.int32)
        e2p_box_target_counts_nonchild = np.array([0, 0, 0, 0], dtype=np.int32)
        e2p_box_target_counts_nonchild[source_box_nr] = ntargets

        evt, (pot, ) = e2p(
            queue,
            src_expansions=mpoles,
            src_base_ibox=0,
            target_boxes=e2p_target_boxes,
            box_target_starts=e2p_box_target_starts,
            box_target_counts_nonchild=e2p_box_target_counts_nonchild,
            centers=centers,
            targets=targets,
            rscale=rscale,
            out_host=True,
            **extra_kwargs)

        return pot

    for order in orders:
        m_expn = mpole_expn_class(knl, order=order)
        l_expn = local_expn_class(knl, order=order)

        from sumpy import P2EFromSingleBox, E2PFromSingleBox, P2P, E2EFromCSR
        p2m = P2EFromSingleBox(ctx, m_expn)
        m2m = E2EFromCSR(ctx, m_expn, m_expn)
        m2p = E2PFromSingleBox(ctx, m_expn, out_kernels)
        m2l = E2EFromCSR(ctx, m_expn, l_expn)
        l2l = E2EFromCSR(ctx, l_expn, l_expn)
        l2p = E2PFromSingleBox(ctx, l_expn, out_kernels)
        p2p = P2P(ctx, out_kernels, exclude_self=False)

        fp = FieldPlotter(centers[:, -1], extent=0.3, npoints=res)
        targets = fp.points

        # {{{ compute (direct) reference solution

        evt, (pot_direct, ) = p2p(queue,
                                  targets,
                                  sources, (strengths, ),
                                  out_host=True,
                                  **extra_kwargs)

        # }}}

        m1_rscale = 0.5
        m2_rscale = 0.25
        l1_rscale = 0.5
        l2_rscale = 0.25

        # {{{ apply P2M

        p2m_source_boxes = np.array([0], dtype=np.int32)

        # These are indexed by global box numbers.
        p2m_box_source_starts = np.array([0, 0, 0, 0], dtype=np.int32)
        p2m_box_source_counts_nonchild = np.array([nsources, 0, 0, 0],
                                                  dtype=np.int32)

        evt, (mpoles, ) = p2m(
            queue,
            source_boxes=p2m_source_boxes,
            box_source_starts=p2m_box_source_starts,
            box_source_counts_nonchild=p2m_box_source_counts_nonchild,
            centers=centers,
            sources=sources,
            strengths=(strengths, ),
            nboxes=nboxes,
            rscale=m1_rscale,
            tgt_base_ibox=0,

            #flags="print_hl_wrapper",
            out_host=True,
            **extra_kwargs)

        # }}}

        ntargets = targets.shape[-1]

        pot = eval_at(m2p, 0, m1_rscale)

        err = la.norm((pot - pot_direct) / res**2)
        err = err / (la.norm(pot_direct) / res**2)

        pconv_verifier_p2m2p.add_data_point(order, err)

        # {{{ apply M2M

        m2m_target_boxes = np.array([1], dtype=np.int32)
        m2m_src_box_starts = np.array([0, 1], dtype=np.int32)
        m2m_src_box_lists = np.array([0], dtype=np.int32)

        evt, (mpoles, ) = m2m(
            queue,
            src_expansions=mpoles,
            src_base_ibox=0,
            tgt_base_ibox=0,
            ntgt_level_boxes=mpoles.shape[0],
            target_boxes=m2m_target_boxes,
            src_box_starts=m2m_src_box_starts,
            src_box_lists=m2m_src_box_lists,
            centers=centers,
            src_rscale=m1_rscale,
            tgt_rscale=m2_rscale,

            #flags="print_hl_cl",
            out_host=True,
            **extra_kwargs)

        # }}}

        pot = eval_at(m2p, 1, m2_rscale)

        err = la.norm((pot - pot_direct) / res**2)
        err = err / (la.norm(pot_direct) / res**2)

        pconv_verifier_p2m2m2p.add_data_point(order, err)

        # {{{ apply M2L

        m2l_target_boxes = np.array([2], dtype=np.int32)
        m2l_src_box_starts = np.array([0, 1], dtype=np.int32)
        m2l_src_box_lists = np.array([1], dtype=np.int32)

        evt, (mpoles, ) = m2l(
            queue,
            src_expansions=mpoles,
            src_base_ibox=0,
            tgt_base_ibox=0,
            ntgt_level_boxes=mpoles.shape[0],
            target_boxes=m2l_target_boxes,
            src_box_starts=m2l_src_box_starts,
            src_box_lists=m2l_src_box_lists,
            centers=centers,
            src_rscale=m2_rscale,
            tgt_rscale=l1_rscale,

            #flags="print_hl_cl",
            out_host=True,
            **extra_kwargs)

        # }}}

        pot = eval_at(l2p, 2, l1_rscale)

        err = la.norm((pot - pot_direct) / res**2)
        err = err / (la.norm(pot_direct) / res**2)

        pconv_verifier_p2m2m2l2p.add_data_point(order, err)

        # {{{ apply L2L

        l2l_target_boxes = np.array([3], dtype=np.int32)
        l2l_src_box_starts = np.array([0, 1], dtype=np.int32)
        l2l_src_box_lists = np.array([2], dtype=np.int32)

        evt, (mpoles, ) = l2l(
            queue,
            src_expansions=mpoles,
            src_base_ibox=0,
            tgt_base_ibox=0,
            ntgt_level_boxes=mpoles.shape[0],
            target_boxes=l2l_target_boxes,
            src_box_starts=l2l_src_box_starts,
            src_box_lists=l2l_src_box_lists,
            centers=centers,
            src_rscale=l1_rscale,
            tgt_rscale=l2_rscale,

            #flags="print_hl_wrapper",
            out_host=True,
            **extra_kwargs)

        # }}}

        pot = eval_at(l2p, 3, l2_rscale)

        err = la.norm((pot - pot_direct) / res**2)
        err = err / (la.norm(pot_direct) / res**2)

        pconv_verifier_full.add_data_point(order, err)

    for name, verifier in [
        ("p2m2p", pconv_verifier_p2m2p),
        ("p2m2m2p", pconv_verifier_p2m2m2p),
        ("p2m2m2l2p", pconv_verifier_p2m2m2l2p),
        ("full", pconv_verifier_full),
    ]:
        print(30 * "-")
        print(name)
        print(30 * "-")
        print(verifier)
        print(30 * "-")
        verifier()
Пример #7
0
def test_p2e2p(ctx_factory, base_knl, expn_class, order,
               with_source_derivative):
    #logging.basicConfig(level=logging.INFO)

    from sympy.core.cache import clear_cache
    clear_cache()

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

    np.random.seed(17)

    res = 100
    nsources = 100

    extra_kwargs = {}
    if isinstance(base_knl, HelmholtzKernel):
        if base_knl.allow_evanescent:
            extra_kwargs["k"] = 0.2 * (0.707 + 0.707j)
        else:
            extra_kwargs["k"] = 0.2
    if isinstance(base_knl, StokesletKernel):
        extra_kwargs["mu"] = 0.2

    if with_source_derivative:
        knl = DirectionalSourceDerivative(base_knl, "dir_vec")
    else:
        knl = base_knl

    out_kernels = [
        knl,
        AxisTargetDerivative(0, knl),
    ]
    expn = expn_class(knl, order=order)

    from sumpy import P2EFromSingleBox, E2PFromSingleBox, P2P
    p2e = P2EFromSingleBox(ctx, expn, kernels=[knl])
    e2p = E2PFromSingleBox(ctx, expn, kernels=out_kernels)
    p2p = P2P(ctx, out_kernels, exclude_self=False)

    from pytools.convergence import EOCRecorder
    eoc_rec_pot = EOCRecorder()
    eoc_rec_grad_x = EOCRecorder()

    from sumpy.expansion.local import LocalExpansionBase
    if issubclass(expn_class, LocalExpansionBase):
        h_values = [1 / 5, 1 / 7, 1 / 20]
    else:
        h_values = [1 / 2, 1 / 3, 1 / 5]

    center = np.array([2, 1, 0][:knl.dim], np.float64)
    sources = (0.7 *
               (-0.5 + np.random.rand(knl.dim, nsources).astype(np.float64)) +
               center[:, np.newaxis])

    strengths = np.ones(nsources, dtype=np.float64) * (1 / nsources)

    source_boxes = np.array([0], dtype=np.int32)
    box_source_starts = np.array([0], dtype=np.int32)
    box_source_counts_nonchild = np.array([nsources], dtype=np.int32)

    extra_source_kwargs = extra_kwargs.copy()
    if isinstance(knl, DirectionalSourceDerivative):
        alpha = np.linspace(0, 2 * np.pi, nsources, np.float64)
        dir_vec = np.vstack([np.cos(alpha), np.sin(alpha)])
        extra_source_kwargs["dir_vec"] = dir_vec

    from sumpy.visualization import FieldPlotter

    for h in h_values:
        if issubclass(expn_class, LocalExpansionBase):
            loc_center = np.array([5.5, 0.0, 0.0][:knl.dim]) + center
            centers = np.array(loc_center,
                               dtype=np.float64).reshape(knl.dim, 1)
            fp = FieldPlotter(loc_center, extent=h, npoints=res)
        else:
            eval_center = np.array([1 / h, 0.0, 0.0][:knl.dim]) + center
            fp = FieldPlotter(eval_center, extent=0.1, npoints=res)
            centers = (np.array([0.0, 0.0, 0.0][:knl.dim],
                                dtype=np.float64).reshape(knl.dim, 1) +
                       center[:, np.newaxis])

        targets = fp.points

        rscale = 0.5  # pick something non-1

        # {{{ apply p2e

        evt, (mpoles, ) = p2e(
            queue,
            source_boxes=source_boxes,
            box_source_starts=box_source_starts,
            box_source_counts_nonchild=box_source_counts_nonchild,
            centers=centers,
            sources=sources,
            strengths=(strengths, ),
            nboxes=1,
            tgt_base_ibox=0,
            rscale=rscale,

            #flags="print_hl_cl",
            out_host=True,
            **extra_source_kwargs)

        # }}}

        # {{{ apply e2p

        ntargets = targets.shape[-1]

        box_target_starts = np.array([0], dtype=np.int32)
        box_target_counts_nonchild = np.array([ntargets], dtype=np.int32)

        evt, (
            pot,
            grad_x,
        ) = e2p(
            queue,
            src_expansions=mpoles,
            src_base_ibox=0,
            target_boxes=source_boxes,
            box_target_starts=box_target_starts,
            box_target_counts_nonchild=box_target_counts_nonchild,
            centers=centers,
            targets=targets,
            rscale=rscale,

            #flags="print_hl_cl",
            out_host=True,
            **extra_kwargs)

        # }}}

        # {{{ compute (direct) reference solution

        evt, (
            pot_direct,
            grad_x_direct,
        ) = p2p(queue,
                targets,
                sources, (strengths, ),
                out_host=True,
                **extra_source_kwargs)

        err_pot = la.norm((pot - pot_direct) / res**2)
        err_grad_x = la.norm((grad_x - grad_x_direct) / res**2)

        if 1:
            err_pot = err_pot / la.norm((pot_direct) / res**2)
            err_grad_x = err_grad_x / la.norm((grad_x_direct) / res**2)

        if 0:
            import matplotlib.pyplot as pt
            from matplotlib.colors import Normalize

            pt.subplot(131)
            im = fp.show_scalar_in_matplotlib(pot.real)
            im.set_norm(Normalize(vmin=-0.1, vmax=0.1))

            pt.subplot(132)
            im = fp.show_scalar_in_matplotlib(pot_direct.real)
            im.set_norm(Normalize(vmin=-0.1, vmax=0.1))
            pt.colorbar()

            pt.subplot(133)
            im = fp.show_scalar_in_matplotlib(
                np.log10(1e-15 + np.abs(pot - pot_direct)))
            im.set_norm(Normalize(vmin=-6, vmax=1))

            pt.colorbar()
            pt.show()

        # }}}

        eoc_rec_pot.add_data_point(h, err_pot)
        eoc_rec_grad_x.add_data_point(h, err_grad_x)

    print(expn_class, knl, order)
    print("POTENTIAL:")
    print(eoc_rec_pot)
    print("X TARGET DERIVATIVE:")
    print(eoc_rec_grad_x)

    tgt_order = order + 1
    if issubclass(expn_class, LocalExpansionBase):
        tgt_order_grad = tgt_order - 1
        slack = 0.7
        grad_slack = 0.5
    else:
        tgt_order_grad = tgt_order + 1

        slack = 0.5
        grad_slack = 1

        if order <= 2:
            slack += 1
            grad_slack += 1

    if isinstance(knl, DirectionalSourceDerivative):
        slack += 1
        grad_slack += 2

    if isinstance(base_knl, DirectionalSourceDerivative):
        slack += 1
        grad_slack += 2

    if isinstance(base_knl, HelmholtzKernel):
        if base_knl.allow_evanescent:
            slack += 0.5
            grad_slack += 0.5

        if issubclass(expn_class, VolumeTaylorMultipoleExpansionBase):
            slack += 0.3
            grad_slack += 0.3

    assert eoc_rec_pot.order_estimate() > tgt_order - slack
    assert eoc_rec_grad_x.order_estimate() > tgt_order_grad - grad_slack
Пример #8
0
def test_pyfmmlib_fmm(ctx_getter, dims, use_dipoles, helmholtz_k):
    logging.basicConfig(level=logging.INFO)

    from pytest import importorskip
    importorskip("pyfmmlib")

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

    nsources = 3000
    ntargets = 1000
    dtype = np.float64

    sources = p_normal(queue, nsources, dims, dtype, seed=15)
    targets = (p_normal(queue, ntargets, dims, dtype, seed=18) +
               np.array([2, 0, 0])[:dims])

    sources_host = particle_array_to_host(sources)
    targets_host = particle_array_to_host(targets)

    from boxtree import TreeBuilder
    tb = TreeBuilder(ctx)

    tree, _ = tb(queue,
                 sources,
                 targets=targets,
                 max_particles_in_box=30,
                 debug=True)

    from boxtree.traversal import FMMTraversalBuilder
    tbuild = FMMTraversalBuilder(ctx)
    trav, _ = tbuild(queue, tree, debug=True)

    trav = trav.get(queue=queue)

    from pyopencl.clrandom import PhiloxGenerator
    rng = PhiloxGenerator(queue.context, seed=20)

    weights = rng.uniform(queue, nsources, dtype=np.float64).get()
    #weights = np.ones(nsources)

    if use_dipoles:
        np.random.seed(13)
        dipole_vec = np.random.randn(dims, nsources)
    else:
        dipole_vec = None

    if dims == 2 and helmholtz_k == 0:
        base_nterms = 20
    else:
        base_nterms = 10

    def fmm_level_to_nterms(tree, lev):
        result = base_nterms

        if lev < 3 and helmholtz_k:
            # exercise order-varies-by-level capability
            result += 5

        if use_dipoles:
            result += 1

        return result

    from boxtree.pyfmmlib_integration import FMMLibExpansionWrangler
    wrangler = FMMLibExpansionWrangler(trav.tree,
                                       helmholtz_k,
                                       fmm_level_to_nterms=fmm_level_to_nterms,
                                       dipole_vec=dipole_vec)

    from boxtree.fmm import drive_fmm

    timing_data = {}
    pot = drive_fmm(trav, wrangler, weights, timing_data=timing_data)
    print(timing_data)
    assert timing_data

    # {{{ ref fmmlib computation

    logger.info("computing direct (reference) result")

    import pyfmmlib
    fmmlib_routine = getattr(
        pyfmmlib, "%spot%s%ddall%s_vec" %
        (wrangler.eqn_letter, "fld" if dims == 3 else "grad", dims,
         "_dp" if use_dipoles else ""))

    kwargs = {}
    if dims == 3:
        kwargs["iffld"] = False
    else:
        kwargs["ifgrad"] = False
        kwargs["ifhess"] = False

    if use_dipoles:
        if helmholtz_k == 0 and dims == 2:
            kwargs["dipstr"] = -weights * (dipole_vec[0] + 1j * dipole_vec[1])
        else:
            kwargs["dipstr"] = weights
            kwargs["dipvec"] = dipole_vec
    else:
        kwargs["charge"] = weights
    if helmholtz_k:
        kwargs["zk"] = helmholtz_k

    ref_pot = wrangler.finalize_potentials(
        fmmlib_routine(sources=sources_host.T,
                       targets=targets_host.T,
                       **kwargs)[0])

    rel_err = la.norm(pot - ref_pot, np.inf) / la.norm(ref_pot, np.inf)
    logger.info("relative l2 error vs fmmlib direct: %g" % rel_err)
    assert rel_err < 1e-5, rel_err

    # }}}

    # {{{ check against sumpy

    try:
        import sumpy  # noqa
    except ImportError:
        have_sumpy = False
        from warnings import warn
        warn("sumpy unavailable: cannot compute independent reference "
             "values for pyfmmlib")
    else:
        have_sumpy = True

    if have_sumpy:
        from sumpy.kernel import (LaplaceKernel, HelmholtzKernel,
                                  DirectionalSourceDerivative)
        from sumpy.p2p import P2P

        sumpy_extra_kwargs = {}
        if helmholtz_k:
            knl = HelmholtzKernel(dims)
            sumpy_extra_kwargs["k"] = helmholtz_k
        else:
            knl = LaplaceKernel(dims)

        if use_dipoles:
            knl = DirectionalSourceDerivative(knl)
            sumpy_extra_kwargs["src_derivative_dir"] = dipole_vec

        p2p = P2P(ctx, [knl], exclude_self=False)

        evt, (sumpy_ref_pot, ) = p2p(queue,
                                     targets,
                                     sources, [weights],
                                     out_host=True,
                                     **sumpy_extra_kwargs)

        sumpy_rel_err = (la.norm(pot - sumpy_ref_pot, np.inf) /
                         la.norm(sumpy_ref_pot, np.inf))

        logger.info("relative l2 error vs sumpy direct: %g" % sumpy_rel_err)
        assert sumpy_rel_err < 1e-5, sumpy_rel_err
Пример #9
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=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),
    ])
Пример #10
0
def test_p2p_direct(ctx_factory, exclude_self, factor, lpot_id):
    logging.basicConfig(level=logging.INFO)

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

    ndim = 2
    nblks = 10
    mode_nr = 25

    from sumpy.kernel import LaplaceKernel, DirectionalSourceDerivative
    if lpot_id == 1:
        lknl = LaplaceKernel(ndim)
    elif lpot_id == 2:
        lknl = LaplaceKernel(ndim)
        lknl = DirectionalSourceDerivative(lknl, dir_vec_name="dsource_vec")
    else:
        raise ValueError("unknow lpot_id")

    from sumpy.p2p import P2P
    lpot = P2P(ctx, [lknl], exclude_self=exclude_self)

    from sumpy.p2p import P2PMatrixGenerator
    mat_gen = P2PMatrixGenerator(ctx, [lknl], exclude_self=exclude_self)

    from sumpy.p2p import P2PMatrixBlockGenerator
    blk_gen = P2PMatrixBlockGenerator(ctx, [lknl], exclude_self=exclude_self)

    for n in [200, 300, 400]:
        targets, sources, _, _, sigma = \
            _build_geometry(queue, n, mode_nr, target_radius=1.2)

        h = 2 * np.pi / n
        strengths = (sigma * h, )

        tgtindices = _build_block_index(queue, n, nblks, factor)
        srcindices = _build_block_index(queue, n, nblks, factor)
        index_set = MatrixBlockIndexRanges(ctx, tgtindices, srcindices)

        extra_kwargs = {}
        if exclude_self:
            extra_kwargs["target_to_source"] = \
                cl.array.arange(queue, 0, n, dtype=np.int)
        if lpot_id == 2:
            from pytools.obj_array import make_obj_array
            extra_kwargs["dsource_vec"] = \
                    vector_to_device(queue, make_obj_array(np.ones((ndim, n))))

        _, (result_lpot, ) = lpot(queue,
                                  targets=targets,
                                  sources=sources,
                                  strength=strengths,
                                  **extra_kwargs)
        result_lpot = result_lpot.get()

        _, (mat, ) = mat_gen(queue,
                             targets=targets,
                             sources=sources,
                             **extra_kwargs)
        mat = mat.get()
        result_mat = mat.dot(strengths[0].get())

        _, (blk, ) = blk_gen(queue,
                             targets=targets,
                             sources=sources,
                             index_set=index_set,
                             **extra_kwargs)
        blk = blk.get()

        eps = 1.0e-10 * la.norm(result_lpot)
        assert la.norm(result_mat - result_lpot) < eps

        index_set = index_set.get(queue)
        for i in range(index_set.nblocks):
            assert la.norm(
                index_set.block_take(blk, i) - index_set.take(mat, i)) < eps
Пример #11
0
def draw_pot_figure(aspect_ratio,
                    nsrc=100,
                    novsmp=None,
                    helmholtz_k=0,
                    what_operator="S",
                    what_operator_lpot=None,
                    order=4,
                    ovsmp_center_exp=0.66,
                    force_center_side=None):

    import logging
    logging.basicConfig(level=logging.INFO)

    if novsmp is None:
        novsmp = 4 * nsrc

    if what_operator_lpot is None:
        what_operator_lpot = what_operator

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

    # {{{ make plot targets

    center = np.asarray([0, 0], dtype=np.float64)
    from sumpy.visualization import FieldPlotter
    fp = FieldPlotter(center, npoints=1000, extent=6)

    # }}}

    # {{{ make p2p kernel calculator

    from sumpy.p2p import P2P
    from sumpy.kernel import LaplaceKernel, HelmholtzKernel
    from sumpy.expansion.local import H2DLocalExpansion, LineTaylorLocalExpansion
    if helmholtz_k:
        if isinstance(helmholtz_k, complex):
            knl = HelmholtzKernel(2, allow_evanescent=True)
            expn_class = H2DLocalExpansion
            knl_kwargs = {"k": helmholtz_k}
        else:
            knl = HelmholtzKernel(2)
            expn_class = H2DLocalExpansion
            knl_kwargs = {"k": helmholtz_k}

    else:
        knl = LaplaceKernel(2)
        expn_class = LineTaylorLocalExpansion
        knl_kwargs = {}

    vol_knl = process_kernel(knl, what_operator)
    p2p = P2P(ctx, [vol_knl], exclude_self=False, value_dtypes=np.complex128)

    lpot_knl = process_kernel(knl, what_operator_lpot)

    from sumpy.qbx import LayerPotential
    lpot = LayerPotential(ctx, [expn_class(lpot_knl, order=order)],
                          value_dtypes=np.complex128)

    # }}}

    # {{{ set up geometry

    # r,a,b match the corresponding letters from G. J. Rodin and O. Steinbach,
    # Boundary Element Preconditioners for problems defined on slender domains.
    # http://dx.doi.org/10.1137/S1064827500372067

    a = 1
    b = 1 / aspect_ratio

    def map_to_curve(t):
        t = t * (2 * np.pi)

        x = a * np.cos(t)
        y = b * np.sin(t)

        w = (np.zeros_like(t) + 1) / len(t)

        return x, y, w

    from curve import CurveGrid

    native_t = np.linspace(0, 1, nsrc, endpoint=False)
    native_x, native_y, native_weights = map_to_curve(native_t)
    native_curve = CurveGrid(native_x, native_y)

    ovsmp_t = np.linspace(0, 1, novsmp, endpoint=False)
    ovsmp_x, ovsmp_y, ovsmp_weights = map_to_curve(ovsmp_t)
    ovsmp_curve = CurveGrid(ovsmp_x, ovsmp_y)

    curve_len = np.sum(ovsmp_weights * ovsmp_curve.speed)
    hovsmp = curve_len / novsmp
    center_dist = 5 * hovsmp

    if force_center_side is not None:
        center_side = force_center_side * np.ones(len(native_curve))
    else:
        center_side = -np.sign(native_curve.mean_curvature)

    centers = (native_curve.pos +
               center_side[:, np.newaxis] * center_dist * native_curve.normal)

    #native_curve.plot()
    #pt.show()

    volpot_kwargs = knl_kwargs.copy()
    lpot_kwargs = knl_kwargs.copy()

    if what_operator == "D":
        volpot_kwargs["src_derivative_dir"] = native_curve.normal

    if what_operator_lpot == "D":
        lpot_kwargs["src_derivative_dir"] = ovsmp_curve.normal

    if what_operator_lpot == "S'":
        lpot_kwargs["tgt_derivative_dir"] = native_curve.normal

    # }}}

    if 0:
        # {{{ build matrix

        from fourier import make_fourier_interp_matrix
        fim = make_fourier_interp_matrix(novsmp, nsrc)
        from sumpy.tools import build_matrix
        from scipy.sparse.linalg import LinearOperator

        def apply_lpot(x):
            xovsmp = np.dot(fim, x)
            evt, (y, ) = lpot(queue,
                              native_curve.pos,
                              ovsmp_curve.pos,
                              centers,
                              [xovsmp * ovsmp_curve.speed * ovsmp_weights],
                              expansion_radii=np.ones(centers.shape[1]),
                              **lpot_kwargs)

            return y

        op = LinearOperator((nsrc, nsrc), apply_lpot)
        mat = build_matrix(op, dtype=np.complex128)
        w, v = la.eig(mat)
        pt.plot(w.real, "o-")
        #import sys; sys.exit(0)
        return

        # }}}

    # {{{ compute potentials

    mode_nr = 0
    density = np.cos(mode_nr * 2 * np.pi * native_t).astype(np.complex128)
    ovsmp_density = np.cos(mode_nr * 2 * np.pi * ovsmp_t).astype(np.complex128)
    evt, (vol_pot, ) = p2p(queue, fp.points, native_curve.pos,
                           [native_curve.speed * native_weights * density],
                           **volpot_kwargs)

    evt, (curve_pot, ) = lpot(
        queue,
        native_curve.pos,
        ovsmp_curve.pos,
        centers, [ovsmp_density * ovsmp_curve.speed * ovsmp_weights],
        expansion_radii=np.ones(centers.shape[1]),
        **lpot_kwargs)

    # }}}

    if 0:
        # {{{ plot on-surface potential in 2D

        pt.plot(curve_pot, label="pot")
        pt.plot(density, label="dens")
        pt.legend()
        pt.show()

        # }}}

    fp.write_vtk_file("potential.vts", [("potential", vol_pot.real)])

    if 0:
        # {{{ 2D false-color plot

        pt.clf()
        plotval = np.log10(1e-20 + np.abs(vol_pot))
        im = fp.show_scalar_in_matplotlib(plotval.real)
        from matplotlib.colors import Normalize
        im.set_norm(Normalize(vmin=-2, vmax=1))

        src = native_curve.pos
        pt.plot(src[:, 0], src[:, 1], "o-k")
        # close the curve
        pt.plot(src[-1::-len(src) + 1, 0], src[-1::-len(src) + 1, 1], "o-k")

        #pt.gca().set_aspect("equal", "datalim")
        cb = pt.colorbar(shrink=0.9)
        cb.set_label(r"$\log_{10}(\mathdefault{Error})$")
        #from matplotlib.ticker import NullFormatter
        #pt.gca().xaxis.set_major_formatter(NullFormatter())
        #pt.gca().yaxis.set_major_formatter(NullFormatter())
        fp.set_matplotlib_limits()

        # }}}
    else:
        # {{{ 3D plots

        plotval_vol = vol_pot.real
        plotval_c = curve_pot.real

        scale = 1

        if 0:
            # crop singularities--doesn't work very well
            neighbors = [
                np.roll(plotval_vol, 3, 0),
                np.roll(plotval_vol, -3, 0),
                np.roll(plotval_vol, 6, 0),
                np.roll(plotval_vol, -6, 0),
            ]
            avg = np.average(np.abs(plotval_vol))
            outlier_flag = sum(np.abs(plotval_vol - nb)
                               for nb in neighbors) > avg
            plotval_vol[outlier_flag] = sum(
                nb[outlier_flag] for nb in neighbors) / len(neighbors)

        fp.show_scalar_in_mayavi(scale * plotval_vol, max_val=1)
        from mayavi import mlab
        mlab.colorbar()
        if 1:
            mlab.points3d(native_curve.pos[0],
                          native_curve.pos[1],
                          scale * plotval_c,
                          scale_factor=0.02)
        mlab.show()
Пример #12
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