def discr_rel_error(actx, discr, x, xref, p=None): from pytential import norm ref_norm = actx.to_numpy(norm(discr, xref, p=p)) if ref_norm < 1.0e-14: ref_norm = 1 diff_norm = actx.to_numpy(norm(discr, x - xref, p=p)) return diff_norm / ref_norm
stall_iterations=0, hard_failure=True) result = bind(places, sym.real(sym_result))( actx, sigma=actx.np.real(result.solution), **solution.context) ref_result = solution.exact(actx, density_discr) # }}} from pytential import norm h_max = actx.to_numpy( bind(places, sym.h_max(places.ambient_dim))(actx) ) error = actx.to_numpy( norm(density_discr, result - ref_result, p=2) / norm(density_discr, ref_result, p=2) ) eoc.add_data_point(h_max, error) logger.info("resolution %3d h_max %.5e rel_error %.5e", resolution, h_max, error) if not visualize: continue from meshmode.discretization.visualization import make_visualizer vis = make_visualizer(actx, density_discr, case.target_order) filename = f"beltrami_{case.name}_{solution.name}_{resolution}.vtu" vis.write_vtk_file(filename, [
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
def scat_norm(f): return norm(qbx, queue, f, p=np.inf)
def test_ellipse_eigenvalues(ctx_factory, ellipse_aspect, mode_nr, qbx_order, force_direct, visualize=False): logging.basicConfig(level=logging.INFO) print("ellipse_aspect: %s, mode_nr: %d, qbx_order: %d" % (ellipse_aspect, mode_nr, qbx_order)) cl_ctx = ctx_factory() queue = cl.CommandQueue(cl_ctx) actx = PyOpenCLArrayContext(queue) target_order = 8 from meshmode.discretization import Discretization from meshmode.discretization.poly_element import \ InterpolatoryQuadratureSimplexGroupFactory from pytential.qbx import QBXLayerPotentialSource from pytools.convergence import EOCRecorder s_eoc_rec = EOCRecorder() d_eoc_rec = EOCRecorder() sp_eoc_rec = EOCRecorder() if ellipse_aspect != 1: nelements_values = [60, 100, 150, 200] else: nelements_values = [30, 70] # See # # [1] G. J. Rodin and O. Steinbach, "Boundary Element Preconditioners # for Problems Defined on Slender Domains", SIAM Journal on Scientific # Computing, Vol. 24, No. 4, pg. 1450, 2003. # https://dx.doi.org/10.1137/S1064827500372067 for nelements in nelements_values: mesh = make_curve_mesh(partial(ellipse, ellipse_aspect), np.linspace(0, 1, nelements + 1), target_order) fmm_order = 12 if force_direct: fmm_order = False pre_density_discr = Discretization( actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order)) qbx = QBXLayerPotentialSource( pre_density_discr, 4 * target_order, qbx_order, fmm_order=fmm_order, _expansions_in_tree_have_extent=True, ) places = GeometryCollection(qbx) density_discr = places.get_discretization(places.auto_source.geometry) from meshmode.dof_array import thaw, flatten nodes = thaw(actx, density_discr.nodes()) if visualize: # plot geometry, centers, normals centers = bind(places, sym.expansion_centers(qbx.ambient_dim, +1))(actx) normals = bind(places, sym.normal(qbx.ambient_dim))(actx).as_vector(object) nodes_h = np.array( [actx.to_numpy(axis) for axis in flatten(nodes)]) centers_h = np.array( [actx.to_numpy(axis) for axis in flatten(centers)]) normals_h = np.array( [actx.to_numpy(axis) for axis in flatten(normals)]) pt.plot(nodes_h[0], nodes_h[1], "x-") pt.plot(centers_h[0], centers_h[1], "o") pt.quiver(nodes_h[0], nodes_h[1], normals_h[0], normals_h[1]) pt.gca().set_aspect("equal") pt.show() angle = actx.np.arctan2(nodes[1] * ellipse_aspect, nodes[0]) ellipse_fraction = ((1 - ellipse_aspect) / (1 + ellipse_aspect))**mode_nr # (2.6) in [1] J = actx.np.sqrt( # noqa actx.np.sin(angle)**2 + (1 / ellipse_aspect)**2 * actx.np.cos(angle)**2) from sumpy.kernel import LaplaceKernel lap_knl = LaplaceKernel(2) # {{{ single layer sigma_sym = sym.var("sigma") s_sigma_op = sym.S(lap_knl, sigma_sym, qbx_forced_limit=+1) sigma = actx.np.cos(mode_nr * angle) / J s_sigma = bind(places, s_sigma_op)(actx, sigma=sigma) # SIGN BINGO! :) s_eigval = 1 / (2 * mode_nr) * (1 + (-1)**mode_nr * ellipse_fraction) # (2.12) in [1] s_sigma_ref = s_eigval * J * sigma if 0: #pt.plot(s_sigma.get(), label="result") #pt.plot(s_sigma_ref.get(), label="ref") pt.plot(actx.to_numpy(flatten(s_sigma_ref - s_sigma)), label="err") pt.legend() pt.show() h_max = bind(places, sym.h_max(qbx.ambient_dim))(actx) s_err = (norm(density_discr, s_sigma - s_sigma_ref) / norm(density_discr, s_sigma_ref)) s_eoc_rec.add_data_point(h_max, s_err) # }}} # {{{ double layer d_sigma_op = sym.D(lap_knl, sigma_sym, qbx_forced_limit="avg") sigma = actx.np.cos(mode_nr * angle) d_sigma = bind(places, d_sigma_op)(actx, sigma=sigma) # SIGN BINGO! :) d_eigval = -(-1)**mode_nr * 1 / 2 * ellipse_fraction d_sigma_ref = d_eigval * sigma if 0: pt.plot(actx.to_numpy(flatten(d_sigma)), label="result") pt.plot(actx.to_numpy(flatten(d_sigma_ref)), label="ref") pt.legend() pt.show() if ellipse_aspect == 1: d_ref_norm = norm(density_discr, sigma) else: d_ref_norm = norm(density_discr, d_sigma_ref) d_err = (norm(density_discr, d_sigma - d_sigma_ref) / d_ref_norm) d_eoc_rec.add_data_point(h_max, d_err) # }}} if ellipse_aspect == 1: # {{{ S' sp_sigma_op = sym.Sp(lap_knl, sym.var("sigma"), qbx_forced_limit="avg") sigma = actx.np.cos(mode_nr * angle) sp_sigma = bind(places, sp_sigma_op)(actx, sigma=sigma) sp_eigval = 0 sp_sigma_ref = sp_eigval * sigma sp_err = (norm(density_discr, sp_sigma - sp_sigma_ref) / norm(density_discr, sigma)) sp_eoc_rec.add_data_point(h_max, sp_err) # }}} print("Errors for S:") print(s_eoc_rec) required_order = qbx_order + 1 assert s_eoc_rec.order_estimate() > required_order - 1.5 print("Errors for D:") print(d_eoc_rec) required_order = qbx_order assert d_eoc_rec.order_estimate() > required_order - 1.5 if ellipse_aspect == 1: print("Errors for S':") print(sp_eoc_rec) required_order = qbx_order assert sp_eoc_rec.order_estimate() > required_order - 1.5
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 vol_discr = Discretization( ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(quad_order)) from meshmode.discretization.connection import make_face_restriction bdry_connection = make_face_restriction( vol_discr, InterpolatoryQuadratureSimplexGroupFactory(quad_order), BTAG_ALL) bdry_discr = bdry_connection.to_discr # }}} # {{{ 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(mesh.ambient_dim) | sym.nodes(mesh.ambient_dim), )(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
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
def rel_err(comp, ref): return actx.to_numpy( norm(density_discr, comp - ref) / norm(density_discr, ref))
def get_green_error(geometry_getter, lpot_kwargs, center, k, vis_error_filename=None, vis_order=TARGET_ORDER): """Return the Green identity error for a geometry. The density function for the Green error is the on-surface restriction of the potential due to a source charge in the exterior of the geometry, whose location is specified. The error is reported relative to the norm of the density. Params: geometry_getter: Geometry getter lpot_kwargs: Constructor args to QBXLayerPotentialSource center: Center of source charge used to obtain the constructed density k: Helmholtz parameter Returns: A dictionary containing Green identity errors in l^2 and l^infty norm """ context = cl.create_some_context(interactive=False) queue = cl.CommandQueue(context) lpot_source = geometry_getter(queue, lpot_kwargs) d = lpot_source.ambient_dim u_sym = sym.var("u") dn_u_sym = sym.var("dn_u") from sumpy.kernel import LaplaceKernel, HelmholtzKernel lap_k_sym = LaplaceKernel(d) if k == 0: k_sym = lap_k_sym knl_kwargs = {} else: k_sym = HelmholtzKernel(d) knl_kwargs = {"k": sym.var("k")} S_part = (sym.S(k_sym, dn_u_sym, qbx_forced_limit=-1, **knl_kwargs)) D_part = (sym.D(k_sym, u_sym, qbx_forced_limit="avg", **knl_kwargs)) sym_op = S_part - D_part - 0.5 * u_sym density_discr = lpot_source.density_discr # {{{ compute values of a solution to the PDE nodes_host = density_discr.nodes().get(queue) normal = bind(density_discr, sym.normal(d))(queue).as_vector(np.object) normal_host = [normal[j].get() for j in range(d)] if k != 0: if d == 2: 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: diff = nodes_host - center[:, np.newaxis] r = la.norm(diff, axis=0) u = np.exp(1j * k * r) / r grad_u = diff * (1j * k * u / r - u / r**2) else: diff = nodes_host - center[:, np.newaxis] dist_squared = np.sum(diff**2, axis=0) dist = np.sqrt(dist_squared) if d == 2: u = np.log(dist) grad_u = diff / dist_squared elif d == 3: u = 1 / dist grad_u = -diff / dist**3 else: assert False dn_u = 0 for i in range(d): dn_u = dn_u + normal_host[i] * grad_u[i] # }}} 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) bound_op = bind(lpot_source, sym_op) error = bound_op(queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=k) scaling_l2 = 1 / norm(density_discr, queue, u_dev, p=2) scaling_linf = 1 / norm(density_discr, queue, u_dev, p="inf") if vis_error_filename is not None: from meshmode.discretization.visualization import make_visualizer bdry_vis = make_visualizer(queue, lpot_source.density_discr, vis_order) bdry_vis.write_vtk_file(vis_error_filename, [ ("green_zero", error), ("u_dev", u_dev), ]) err_l2 = scaling_l2 * norm(density_discr, queue, error, p=2) err_linf = scaling_linf * norm(density_discr, queue, error, p="inf") return dict(err_l2=err_l2, err_linf=err_linf)
def get_green_error(lpot_source, fmm_order, qbx_order, k=0, time=None): 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") dn_u_sym = sym.var("dn_u") from sumpy.kernel import LaplaceKernel, HelmholtzKernel lap_k_sym = LaplaceKernel(d) if k == 0: k_sym = lap_k_sym knl_kwargs = {} else: k_sym = HelmholtzKernel(d) knl_kwargs = {"k": sym.var("k")} S_part = ( # noqa: N806 sym.S(k_sym, dn_u_sym, qbx_forced_limit=-1, **knl_kwargs)) D_part = ( # noqa: N806 sym.D(k_sym, u_sym, qbx_forced_limit="avg", **knl_kwargs)) density_discr = lpot_source.density_discr # {{{ compute values of a solution to the PDE nodes_host = density_discr.nodes().get(queue) normal = bind(density_discr, sym.normal(d))(queue).as_vector(np.object) normal_host = [normal[j].get() for j in range(d)] if k != 0: if d == 2: 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, 2]) diff = nodes_host - center[:, np.newaxis] r = la.norm(diff, axis=0) u = np.exp(1j * k * r) / r grad_u = diff * (1j * k * u / r - u / r**2) else: center = np.array([2, 1, 2])[:d] diff = nodes_host - center[:, np.newaxis] dist_squared = np.sum(diff**2, axis=0) dist = np.sqrt(dist_squared) if d == 2: u = np.log(dist) grad_u = diff / dist_squared elif d == 3: u = 1 / dist grad_u = -diff / dist**3 else: assert False dn_u = 0 for i in range(d): dn_u = dn_u + normal_host[i] * grad_u[i] # }}} 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) bound_S_part = bind(lpot_source, S_part) # noqa: N806 bound_D_part = bind(lpot_source, D_part) # noqa: N806 from time import time as curr_time t_start = curr_time() S_result = bound_S_part( # noqa: N806 queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=k) t_end = curr_time() if time is not None: time[0] = t_end - t_start D_result = bound_D_part( # noqa: N806 queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=k) scaling_l2 = 1 / norm(density_discr, queue, u_dev, p=2) scaling_linf = 1 / norm(density_discr, queue, u_dev, p="inf") error = S_result - D_result - 0.5 * u_dev return (scaling_l2 * norm(density_discr, queue, error, p=2), scaling_linf * norm(density_discr, queue, error, p="inf"))
def rel_err(comp, ref): return ( norm(density_discr, queue, comp - ref) / norm(density_discr, queue, ref))
def obs_norm(f): return norm(obs_discr, queue, f, p=np.inf)
def test_sanity_balls(actx_factory, src_file, dim, mesh_order, visualize=False): pytest.importorskip("pytential") logging.basicConfig(level=logging.INFO) actx = actx_factory() 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, 0.1, 0.05]: 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, target_unit="MM") logger.info("%d elements", mesh.nelements) # {{{ discretizations and connections from meshmode.discretization import Discretization vol_discr = Discretization( actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(quad_order)) from meshmode.discretization.connection import make_face_restriction bdry_connection = make_face_restriction( actx, vol_discr, InterpolatoryQuadratureSimplexGroupFactory(quad_order), BTAG_ALL) bdry_discr = bdry_connection.to_discr # }}} from math import gamma true_surf = 2 * np.pi**(dim / 2) / gamma(dim / 2) true_vol = true_surf / dim vol_x = thaw(vol_discr.nodes(), actx) vol_one = vol_x[0] * 0 + 1 from pytential import norm, integral # noqa comp_vol = integral(vol_discr, 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 = thaw(bdry_discr.nodes(), actx) bdry_one_exact = bdry_x[0] * 0 + 1 bdry_one = bdry_connection(vol_one) intp_err = norm(bdry_discr, bdry_one - bdry_one_exact) assert intp_err < 1e-14 comp_surf = integral(bdry_discr, 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: from meshmode.discretization.visualization import make_visualizer vol_vis = make_visualizer(actx, vol_discr, 7) bdry_vis = make_visualizer(actx, bdry_discr, 7) name = src_file.split("-")[0] vol_vis.write_vtk_file(f"sanity_balls_volume_{name}_{h:g}.vtu", [ ("f", vol_one), ("area_el", bind(vol_discr, sym.area_element(mesh.ambient_dim, mesh.ambient_dim))(actx)), ]) bdry_vis.write_vtk_file(f"sanity_balls_boundary_{name}_{h:g}.vtu", [("f", bdry_one)]) # {{{ check normals point outward normal_outward_check = bind( bdry_discr, sym.normal(mesh.ambient_dim) | sym.nodes(mesh.ambient_dim), )(actx).as_scalar() normal_outward_check = flatten_to_numpy(actx, normal_outward_check > 0) assert normal_outward_check.all(), normal_outward_check # }}} 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
def test_ellipse_eigenvalues(ctx_getter, ellipse_aspect, mode_nr, qbx_order): logging.basicConfig(level=logging.INFO) print("ellipse_aspect: %s, mode_nr: %d, qbx_order: %d" % ( ellipse_aspect, mode_nr, qbx_order)) cl_ctx = ctx_getter() queue = cl.CommandQueue(cl_ctx) target_order = 7 from meshmode.discretization import Discretization from meshmode.discretization.poly_element import \ InterpolatoryQuadratureSimplexGroupFactory from pytential.qbx import QBXLayerPotentialSource from pytools.convergence import EOCRecorder s_eoc_rec = EOCRecorder() d_eoc_rec = EOCRecorder() sp_eoc_rec = EOCRecorder() if ellipse_aspect != 1: nelements_values = [60, 100, 150, 200] else: nelements_values = [30, 70] # See # # [1] G. J. Rodin and O. Steinbach, "Boundary Element Preconditioners # for Problems Defined on Slender Domains", SIAM Journal on Scientific # Computing, Vol. 24, No. 4, pg. 1450, 2003. # http://dx.doi.org/10.1137/S1064827500372067 for nelements in nelements_values: mesh = make_curve_mesh(partial(ellipse, ellipse_aspect), np.linspace(0, 1, nelements+1), target_order) fmm_order = qbx_order if fmm_order > 3: # FIXME: for now fmm_order = False density_discr = Discretization( cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order)) qbx = QBXLayerPotentialSource(density_discr, 4*target_order, qbx_order, fmm_order=fmm_order) nodes = density_discr.nodes().with_queue(queue) if 0: # plot geometry, centers, normals centers = qbx.centers(density_discr, 1) nodes_h = nodes.get() centers_h = [centers[0].get(), centers[1].get()] pt.plot(nodes_h[0], nodes_h[1], "x-") pt.plot(centers_h[0], centers_h[1], "o") normal = bind(qbx, sym.normal())(queue).as_vector(np.object) pt.quiver(nodes_h[0], nodes_h[1], normal[0].get(), normal[1].get()) pt.gca().set_aspect("equal") pt.show() angle = cl.clmath.atan2(nodes[1]*ellipse_aspect, nodes[0]) ellipse_fraction = ((1-ellipse_aspect)/(1+ellipse_aspect))**mode_nr # (2.6) in [1] J = cl.clmath.sqrt( # noqa cl.clmath.sin(angle)**2 + (1/ellipse_aspect)**2 * cl.clmath.cos(angle)**2) # {{{ single layer sigma = cl.clmath.cos(mode_nr*angle)/J s_sigma_op = bind(qbx, sym.S(0, sym.var("sigma"))) s_sigma = s_sigma_op(queue=queue, sigma=sigma) # SIGN BINGO! :) s_eigval = 1/(2*mode_nr) * (1 + (-1)**mode_nr * ellipse_fraction) # (2.12) in [1] s_sigma_ref = s_eigval*J*sigma if 0: #pt.plot(s_sigma.get(), label="result") #pt.plot(s_sigma_ref.get(), label="ref") pt.plot((s_sigma_ref-s_sigma).get(), label="err") pt.legend() pt.show() s_err = ( norm(density_discr, queue, s_sigma - s_sigma_ref) / norm(density_discr, queue, s_sigma_ref)) s_eoc_rec.add_data_point(1/nelements, s_err) # }}} # {{{ double layer sigma = cl.clmath.cos(mode_nr*angle) d_sigma_op = bind(qbx, sym.D(0, sym.var("sigma"))) d_sigma = d_sigma_op(queue=queue, sigma=sigma) # SIGN BINGO! :) d_eigval = -(-1)**mode_nr * 1/2*ellipse_fraction d_sigma_ref = d_eigval*sigma if 0: pt.plot(d_sigma.get(), label="result") pt.plot(d_sigma_ref.get(), label="ref") pt.legend() pt.show() if ellipse_aspect == 1: d_ref_norm = norm(density_discr, queue, sigma) else: d_ref_norm = norm(density_discr, queue, d_sigma_ref) d_err = ( norm(density_discr, queue, d_sigma - d_sigma_ref) / d_ref_norm) d_eoc_rec.add_data_point(1/nelements, d_err) # }}} if ellipse_aspect == 1: # {{{ S' sigma = cl.clmath.cos(mode_nr*angle) sp_sigma_op = bind(qbx, sym.Sp(0, sym.var("sigma"))) sp_sigma = sp_sigma_op(queue=queue, sigma=sigma) sp_eigval = 0 sp_sigma_ref = sp_eigval*sigma sp_err = ( norm(density_discr, queue, sp_sigma - sp_sigma_ref) / norm(density_discr, queue, sigma)) sp_eoc_rec.add_data_point(1/nelements, sp_err) # }}} print("Errors for S:") print(s_eoc_rec) required_order = qbx_order + 1 assert s_eoc_rec.order_estimate() > required_order - 1.5 print("Errors for D:") print(d_eoc_rec) required_order = qbx_order assert d_eoc_rec.order_estimate() > required_order - 1.5 if ellipse_aspect == 1: print("Errors for S':") print(sp_eoc_rec) required_order = qbx_order assert sp_eoc_rec.order_estimate() > required_order - 1.5
def test_3d_jump_relations(ctx_factory, relation, visualize=False): # logging.basicConfig(level=logging.INFO) cl_ctx = ctx_factory() queue = cl.CommandQueue(cl_ctx) actx = PyOpenCLArrayContext(queue) 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_major=2*nel_factor, n_minor=nel_factor) from meshmode.discretization import Discretization from meshmode.discretization.poly_element import \ InterpolatoryQuadratureSimplexGroupFactory pre_discr = Discretization( actx, 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" ) places = GeometryCollection(qbx) density_discr = places.get_discretization(places.auto_source.geometry) 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))) from meshmode.dof_array import thaw x, y, z = thaw(actx, density_discr.nodes()) m = actx.np 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(places, sym.xyz_to_tangential(sym.make_sym_vector("jxyz", 3)))( actx, 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(places, jump_identity_sym) jump_identity = bound_jump_identity(actx, density=density) h_max = bind(places, sym.h_max(qbx.ambient_dim))(actx) err = ( norm(density_discr, jump_identity, np.inf) / norm(density_discr, density, np.inf)) print("ERROR", h_max, err) eoc_rec.add_data_point(h_max, err) # {{{ visualization if visualize and relation == "nxcurls": nxcurlS_ext = bind(places, nxcurlS(+1))(actx, density=density) nxcurlS_avg = bind(places, nxcurlS("avg"))(actx, density=density) jtxyz = bind(places, sym.tangential_to_xyz(density_sym))( actx, density=density) from meshmode.discretization.visualization import make_visualizer bdry_vis = make_visualizer(actx, qbx.density_discr, target_order+3) bdry_normals = bind(places, sym.normal(3))(actx)\ .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": op = sym.Sp(knl, density_sym, qbx_forced_limit=+1) sp_ext = bind(places, op)(actx, density=density) op = sym.Sp(knl, density_sym, qbx_forced_limit="avg") sp_avg = bind(places, op)(actx, density=density) from meshmode.discretization.visualization import make_visualizer bdry_vis = make_visualizer(actx, qbx.density_discr, target_order+3) bdry_normals = bind(places, sym.normal(3))(actx).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
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
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)
def main(): import logging logging.basicConfig(level=logging.INFO) ctx = cl.create_some_context() queue = cl.CommandQueue(ctx) if 1: ext = 0.5 mesh = generate_regular_rect_mesh(a=(-ext / 2, -ext / 2), b=(ext / 2, ext / 2), n=(int(ext / h), int(ext / h))) else: 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.mesh import BTAG_ALL from meshmode.discretization.connection import (make_face_restriction, make_same_mesh_connection) bdry_connection = make_face_restriction( vol_discr, InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order), BTAG_ALL) bdry_discr = bdry_connection.to_discr vol_to_ovsmp_vol = make_same_mesh_connection(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( mesh.ambient_dim))(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 from pymbolic import var d = make_sym_vector("d", 3) r = pymbolic_real_norm_2(d[:-1]) # r3d = pymbolic_real_norm_2(d) #expr = var("log")(r3d) log = var("log") sqrt = var("sqrt") a = d[-1] expr = log(r) expr = log(sqrt(r**2 + a**2)) expr = log(sqrt(r + a**2)) #expr = log(sqrt(r**2 + a**2))-a**2/2/(r**2+a**2) #expr = 2*log(sqrt(r**2 + a**2)) scaling = 1 / (2 * var("pi")) from sumpy.kernel import ExpressionKernel return ExpressionKernel(dim=3, expression=expr, global_scaling_const=scaling, is_complex_valued=False) laplace_2d_in_3d_kernel = get_kernel() layer_pot = LayerPotential( ctx, [LineTaylorLocalExpansion(laplace_2d_in_3d_kernel, order=0)]) targets = cl.array.zeros(queue, (3, ) + vol_x.shape[1:], vol_x.dtype) targets[:2] = vol_x center_dist = 0.125 * np.min( cl.clmath.sqrt( bind(vol_discr, p.area_element(mesh.ambient_dim, mesh.dim))(queue)).get()) centers = make_obj_array( [ci.copy().reshape(vol_discr.nnodes) for ci in targets]) centers[2][:] = center_dist print(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(mesh.ambient_dim, mesh.dim) * p.QWeight())(queue) print("volume: %d source nodes, %d target nodes" % (ovsmp_vol_discr.nnodes, vol_discr.nnodes)) 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), ), expansion_radii=np.zeros(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", dtype=np.float64), 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)
def rel_err(comp, ref): return (norm(density_discr, comp - ref) / norm(density_discr, ref))
def test_3d_jump_relations(actx_factory, relation, visualize=False): # logging.basicConfig(level=logging.INFO) actx = actx_factory() if relation == "div_s": target_order = 3 else: target_order = 4 qbx_order = target_order if relation == "sp": resolutions = [10, 14, 18] else: resolutions = [6, 10, 14] from pytools.convergence import EOCRecorder eoc_rec = EOCRecorder() for nel_factor in resolutions: from meshmode.mesh.generation import generate_torus mesh = generate_torus( 5, 2, n_major=2 * nel_factor, n_minor=nel_factor, order=target_order, ) from meshmode.discretization import Discretization from meshmode.discretization.poly_element import \ InterpolatoryQuadratureSimplexGroupFactory pre_density_discr = Discretization( actx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order)) from pytential.qbx import QBXLayerPotentialSource qbx = QBXLayerPotentialSource(pre_density_discr, fine_order=5 * target_order, qbx_order=qbx_order, fmm_order=qbx_order + 5, fmm_backend="fmmlib") places = GeometryCollection(qbx) density_discr = places.get_discretization(places.auto_source.geometry) from sumpy.kernel import LaplaceKernel knl = LaplaceKernel(places.ambient_dim) def nxcurlS(qbx_forced_limit): sigma_sym = sym.cse(sym.tangential_to_xyz(density_sym), "jxyz") return sym.n_cross( sym.curl( sym.S(knl, sigma_sym, qbx_forced_limit=qbx_forced_limit))) x, y, z = thaw(density_discr.nodes(), actx) 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. jxyz = sym.make_obj_array([ actx.np.cos(0.5 * x) * actx.np.cos(0.5 * y) * actx.np.cos(0.5 * z), actx.np.sin(0.5 * x) * actx.np.cos(0.5 * y) * actx.np.sin(0.5 * z), actx.np.sin(0.5 * x) * actx.np.cos(0.5 * y) * actx.np.cos(0.5 * z), ]) density = bind( places, sym.xyz_to_tangential(sym.make_sym_vector("jxyz", 3)))(actx, jxyz=jxyz) elif relation == "sp": density_sym = sym.var("density") jump_identity_sym = ( 0.5 * density_sym + sym.Sp(knl, density_sym, qbx_forced_limit=+1) - sym.Sp(knl, density_sym, qbx_forced_limit="avg")) density = actx.np.cos(2 * x) * actx.np.cos(2 * y) * actx.np.cos(z) elif relation == "div_s": density_sym = sym.var("density") sigma_sym = sym.normal( places.ambient_dim).as_vector() * density_sym jump_identity_sym = ( sym.div(sym.S(knl, sigma_sym, qbx_forced_limit="avg")) + sym.D(knl, density_sym, qbx_forced_limit="avg")) density = actx.np.cos(2 * x) * actx.np.cos(2 * y) * actx.np.cos(z) else: raise ValueError(f"unexpected value of 'relation': '{relation}'") bound_jump_identity = bind(places, jump_identity_sym) jump_identity = bound_jump_identity(actx, density=density) h_max = actx.to_numpy( bind(places, sym.h_max(places.ambient_dim))(actx)) err = actx.to_numpy( norm(density_discr, jump_identity, np.inf) / norm(density_discr, density, np.inf)) eoc_rec.add_data_point(h_max, err) logging.info("error: nel %d h_max %.5e %.5e", nel_factor, h_max, err) # {{{ visualization if not visualize: continue from meshmode.discretization.visualization import make_visualizer vis = make_visualizer(actx, density_discr, target_order) normals = bind(places, sym.normal(places.ambient_dim).as_vector())(actx) error = actx.np.log10(actx.np.abs(jump_identity) + 1.0e-15) if relation == "nxcurls": nxcurlS_ext = bind(places, nxcurlS(+1))(actx, density=density) nxcurlS_avg = bind(places, nxcurlS("avg"))(actx, density=density) jtxyz = bind(places, sym.tangential_to_xyz(density_sym))(actx, density=density) vis.write_vtk_file(f"source-nxcurls-{nel_factor:03d}.vtu", [ ("jt", jtxyz), ("nxcurlS_ext", nxcurlS_ext), ("nxcurlS_avg", nxcurlS_avg), ("bdry_normals", normals), ("error", error), ]) elif relation == "sp": op = sym.Sp(knl, density_sym, qbx_forced_limit=+1) sp_ext = bind(places, op)(actx, density=density) op = sym.Sp(knl, density_sym, qbx_forced_limit="avg") sp_avg = bind(places, op)(actx, density=density) vis.write_vtk_file(f"source-sp-{nel_factor:03d}.vtu", [ ("density", density), ("sp_ext", sp_ext), ("sp_avg", sp_avg), ("bdry_normals", normals), ("error", error), ]) elif relation == "div_s": vis.write_vtk_file(f"source-div-{nel_factor:03d}.vtu", [ ("density", density), ("bdry_normals", normals), ("error", error), ]) # }}} logger.info("\n%s", str(eoc_rec)) assert eoc_rec.order_estimate() >= qbx_order - 1.5
def scat_norm(f): return norm(density_discr, f, p=np.inf)
grad_u_dev = cl.array.to_device(queue, grad_u) key = (case.qbx_order, case.geometry.mesh_name, resolution, case.expr.zero_op_name) bound_op = bind(qbx, case.expr.get_zero_op(k_sym, **knl_kwargs)) error = bound_op(queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=case.k) if 0: pt.plot(error) pt.show() linf_error_norm = norm(density_discr, queue, error, p=np.inf) print("--->", key, linf_error_norm) h_max = bind(qbx, sym.h_max(qbx.ambient_dim))(queue) eoc_rec.add_data_point(h_max, linf_error_norm) if visualize: from meshmode.discretization.visualization import make_visualizer bdry_vis = make_visualizer(queue, density_discr, target_order) bdry_normals = bind(density_discr, sym.normal(mesh.ambient_dim))(queue)\ .as_vector(dtype=object) bdry_vis.write_vtk_file("source-%s.vtu" % resolution, [ ("u", u_dev), ("bdry_normals", bdry_normals),
def test_identity_convergence(ctx_getter, case, visualize=False): logging.basicConfig(level=logging.INFO) case.check() cl_ctx = ctx_getter() queue = cl.CommandQueue(cl_ctx) # prevent cache 'splosion from sympy.core.cache import clear_cache clear_cache() target_order = 8 from pytools.convergence import EOCRecorder eoc_rec = EOCRecorder() for resolution in ( getattr(case, "resolutions", None) or case.geometry.resolutions ): mesh = case.geometry.get_mesh(resolution, target_order) if mesh is None: break d = mesh.ambient_dim k = case.k lap_k_sym = LaplaceKernel(d) if k == 0: k_sym = lap_k_sym knl_kwargs = {} else: k_sym = HelmholtzKernel(d) knl_kwargs = {"k": sym.var("k")} from meshmode.discretization import Discretization from meshmode.discretization.poly_element import \ InterpolatoryQuadratureSimplexGroupFactory from pytential.qbx import QBXLayerPotentialSource pre_density_discr = Discretization( cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order)) refiner_extra_kwargs = {} if case.k != 0: refiner_extra_kwargs["kernel_length_scale"] = 5/case.k qbx, _ = QBXLayerPotentialSource( pre_density_discr, 4*target_order, case.qbx_order, fmm_order=case.fmm_order, fmm_backend=case.fmm_backend, _expansions_in_tree_have_extent=True, _expansion_stick_out_factor=getattr( case, "_expansion_stick_out_factor", 0), ).with_refinement(**refiner_extra_kwargs) density_discr = qbx.density_discr # {{{ compute values of a solution to the PDE nodes_host = density_discr.nodes().get(queue) normal = bind(density_discr, sym.normal(d))(queue).as_vector(np.object) normal_host = [normal[j].get() for j in range(d)] if k != 0: if d == 2: 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 elif d == 3: center = np.array([3, 1, 2]) diff = nodes_host - center[:, np.newaxis] r = la.norm(diff, axis=0) u = np.exp(1j*k*r) / r grad_u = diff * (1j*k*u/r - u/r**2) else: raise ValueError("invalid dim") else: center = np.array([3, 1, 2])[:d] diff = nodes_host - center[:, np.newaxis] dist_squared = np.sum(diff**2, axis=0) dist = np.sqrt(dist_squared) if d == 2: u = np.log(dist) grad_u = diff/dist_squared elif d == 3: u = 1/dist grad_u = -diff/dist**3 else: assert False dn_u = 0 for i in range(d): dn_u = dn_u + normal_host[i]*grad_u[i] # }}} 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 = (case.qbx_order, case.geometry.mesh_name, resolution, case.expr.zero_op_name) bound_op = bind(qbx, case.expr.get_zero_op(k_sym, **knl_kwargs)) error = bound_op( queue, u=u_dev, dn_u=dn_u_dev, grad_u=grad_u_dev, k=case.k) if 0: pt.plot(error) pt.show() linf_error_norm = norm(density_discr, queue, error, p=np.inf) print("--->", key, linf_error_norm) eoc_rec.add_data_point(qbx.h_max, linf_error_norm) if visualize: from meshmode.discretization.visualization import make_visualizer bdry_vis = make_visualizer(queue, density_discr, target_order) bdry_normals = bind(density_discr, sym.normal(mesh.ambient_dim))(queue)\ .as_vector(dtype=object) bdry_vis.write_vtk_file("source-%s.vtu" % resolution, [ ("u", u_dev), ("bdry_normals", bdry_normals), ("error", error), ]) print(eoc_rec) tgt_order = case.qbx_order - case.expr.order_drop assert eoc_rec.order_estimate() > tgt_order - 1.6