Beispiel #1
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def test_1d_mass_mat_trig(ctx_factory):
    """Check the integral of some trig functions on an interval using the mass
    matrix
    """

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

    from meshmode.mesh.generation import generate_regular_rect_mesh

    mesh = generate_regular_rect_mesh(a=(-4 * np.pi, ),
                                      b=(9 * np.pi, ),
                                      n=(17, ),
                                      order=1)

    discr = DGDiscretizationWithBoundaries(cl_ctx, mesh, order=8)

    x = sym.nodes(1)
    f = bind(discr, sym.cos(x[0])**2)(queue)
    ones = bind(discr, sym.Ones(sym.DD_VOLUME))(queue)

    mass_op = bind(discr, sym.MassOperator()(sym.var("f")))

    num_integral_1 = np.dot(ones.get(), mass_op(queue, f=f))
    num_integral_2 = np.dot(f.get(), mass_op(queue, f=ones))
    num_integral_3 = bind(discr, sym.integral(sym.var("f")))(queue, f=f)

    true_integral = 13 * np.pi / 2
    err_1 = abs(num_integral_1 - true_integral)
    err_2 = abs(num_integral_2 - true_integral)
    err_3 = abs(num_integral_3 - true_integral)

    assert err_1 < 1e-10
    assert err_2 < 1e-10
    assert err_3 < 1e-10
Beispiel #2
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def test_external_call(ctx_factory):
    cl_ctx = ctx_factory()
    queue = cl.CommandQueue(cl_ctx)
    actx = PyOpenCLArrayContext(queue)

    def double(queue, x):
        return 2 * x

    from meshmode.mesh.generation import generate_regular_rect_mesh

    dims = 2

    mesh = generate_regular_rect_mesh(a=(0, ) * dims,
                                      b=(1, ) * dims,
                                      n=(4, ) * dims)
    discr = DGDiscretizationWithBoundaries(actx, mesh, order=1)

    ones = sym.Ones(sym.DD_VOLUME)
    op = (ones * 3 + sym.FunctionSymbol("double")(ones))

    from grudge.function_registry import (base_function_registry,
                                          register_external_function)

    freg = register_external_function(base_function_registry,
                                      "double",
                                      implementation=double,
                                      dd=sym.DD_VOLUME)

    bound_op = bind(discr, op, function_registry=freg)

    result = bound_op(actx, double=double)
    assert actx.to_numpy(flatten(result) == 5).all()
Beispiel #3
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def test_external_call(actx_factory):
    actx = actx_factory()

    def double(queue, x):
        return 2 * x

    dims = 2

    mesh = mgen.generate_regular_rect_mesh(a=(0, ) * dims,
                                           b=(1, ) * dims,
                                           nelements_per_axis=(4, ) * dims)
    discr = DiscretizationCollection(actx, mesh, order=1)

    ones = sym.Ones(dof_desc.DD_VOLUME)
    op = (ones * 3 + sym.FunctionSymbol("double")(ones))

    from grudge.function_registry import (base_function_registry,
                                          register_external_function)

    freg = register_external_function(base_function_registry,
                                      "double",
                                      implementation=double,
                                      dd=dof_desc.DD_VOLUME)

    bound_op = bind(discr, op, function_registry=freg)

    result = bound_op(actx, double=double)
    assert actx.to_numpy(flatten(result) == 5).all()
Beispiel #4
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def integral(arg, dd=None):
    sym = _sym()

    if dd is None:
        dd = sym.DD_VOLUME

    dd = sym.as_dofdesc(dd)

    return sym.NodalSum(dd)(
            arg * sym.cse(
                sym.MassOperator(dd_in=dd)(sym.Ones(dd)),
                "mass_quad_weights",
                sym.cse_scope.DISCRETIZATION))
Beispiel #5
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def test_incorrect_assignment_aggregation(actx_factory, ambient_dim):
    """Tests that the greedy assignemnt aggregation code works on a non-trivial
    expression (on which it didn't work at the time of writing).
    """

    actx = actx_factory()

    target_order = 4

    from meshmode.mesh.generation import generate_regular_rect_mesh
    mesh = generate_regular_rect_mesh(a=(-0.5, ) * ambient_dim,
                                      b=(0.5, ) * ambient_dim,
                                      n=(8, ) * ambient_dim,
                                      order=1)
    discr = DiscretizationCollection(actx, mesh, order=target_order)

    # {{{ test with a relative norm

    from grudge.dof_desc import DD_VOLUME
    dd = DD_VOLUME
    sym_x = sym.make_sym_array("y", ambient_dim, dd=dd)
    sym_y = sym.make_sym_array("y", ambient_dim, dd=dd)

    sym_norm_y = sym.norm(2, sym_y, dd=dd)
    sym_norm_d = sym.norm(2, sym_x - sym_y, dd=dd)
    sym_op = sym_norm_d / sym_norm_y
    logger.info("%s", sym.pretty(sym_op))

    # FIXME: this shouldn't raise a RuntimeError
    with pytest.raises(RuntimeError):
        bind(discr, sym_op)(actx, x=1.0, y=discr.discr_from_dd(dd).nodes())

    # }}}

    # {{{ test with repeated mass inverses

    sym_minv_y = sym.cse(sym.InverseMassOperator()(sym_y), "minv_y")

    sym_u = make_obj_array([0.5 * sym.Ones(dd), 0.0, 0.0])[:ambient_dim]
    sym_div_u = sum(d(u) for d, u in zip(sym.nabla(ambient_dim), sym_u))

    sym_op = sym.MassOperator(dd)(sym_u) \
            + sym.MassOperator(dd)(sym_minv_y * sym_div_u)
    logger.info("%s", sym.pretty(sym_op))

    # FIXME: this shouldn't raise a RuntimeError either
    bind(discr, sym_op)(actx, y=discr.discr_from_dd(dd).nodes())
Beispiel #6
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    def _get_variables_on(dd):
        sym_f = sym.var("f", dd=dd)
        sym_x = sym.nodes(ambient_dim, dd=dd)
        sym_ones = sym.Ones(dd)

        return sym_f, sym_x, sym_ones
Beispiel #7
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def test_mass_surface_area(actx_factory, name):
    actx = actx_factory()

    # {{{ cases

    if name == "2-1-ellipse":
        from mesh_data import EllipseMeshBuilder
        builder = EllipseMeshBuilder(radius=3.1, aspect_ratio=2.0)
        surface_area = _ellipse_surface_area(builder.radius,
                                             builder.aspect_ratio)
    elif name == "spheroid":
        from mesh_data import SpheroidMeshBuilder
        builder = SpheroidMeshBuilder()
        surface_area = _spheroid_surface_area(builder.radius,
                                              builder.aspect_ratio)
    elif name == "box2d":
        from mesh_data import BoxMeshBuilder
        builder = BoxMeshBuilder(ambient_dim=2)
        surface_area = 1.0
    elif name == "box3d":
        from mesh_data import BoxMeshBuilder
        builder = BoxMeshBuilder(ambient_dim=3)
        surface_area = 1.0
    else:
        raise ValueError("unknown geometry name: %s" % name)

    # }}}

    # {{{ convergence

    from pytools.convergence import EOCRecorder
    eoc = EOCRecorder()

    for resolution in builder.resolutions:
        mesh = builder.get_mesh(resolution, builder.mesh_order)
        discr = DiscretizationCollection(actx, mesh, order=builder.order)
        volume_discr = discr.discr_from_dd(dof_desc.DD_VOLUME)

        logger.info("ndofs:     %d", volume_discr.ndofs)
        logger.info("nelements: %d", volume_discr.mesh.nelements)

        # {{{ compute surface area

        dd = dof_desc.DD_VOLUME
        sym_op = sym.NodalSum(dd)(sym.MassOperator(dd, dd)(sym.Ones(dd)))
        approx_surface_area = bind(discr, sym_op)(actx)

        logger.info("surface: got {:.5e} / expected {:.5e}".format(
            approx_surface_area, surface_area))
        area_error = abs(approx_surface_area -
                         surface_area) / abs(surface_area)

        # }}}

        h_max = bind(
            discr,
            sym.h_max_from_volume(discr.ambient_dim, dim=discr.dim,
                                  dd=dd))(actx)
        eoc.add_data_point(h_max, area_error + 1.0e-16)

    # }}}

    logger.info("surface area error\n%s", str(eoc))

    assert eoc.max_error() < 1.0e-14 \
            or eoc.order_estimate() > builder.order