def run_source_refinement_test(ctx_getter, mesh, order, helmholtz_k=None):
cl_ctx = ctx_getter()
queue = cl.CommandQueue(cl_ctx)
from meshmode.discretization import Discretization
from meshmode.discretization.poly_element import (
InterpolatoryQuadratureSimplexGroupFactory)
factory = InterpolatoryQuadratureSimplexGroupFactory(order)
discr = Discretization(cl_ctx, mesh, factory)
from pytential.qbx.refinement import (
RefinerCodeContainer, refine_for_global_qbx)
from pytential.qbx.utils import TreeCodeContainer
lpot_source = QBXLayerPotentialSource(discr,
qbx_order=order, # not used in refinement
fine_order=order)
del discr
expansion_disturbance_tolerance = 0.025
refiner_extra_kwargs = {
"expansion_disturbance_tolerance": expansion_disturbance_tolerance,
}
if helmholtz_k is not None:
refiner_extra_kwargs["kernel_length_scale"] = 5/helmholtz_k
lpot_source, conn = refine_for_global_qbx(
lpot_source,
RefinerCodeContainer(
cl_ctx, TreeCodeContainer(cl_ctx)).get_wrangler(queue),
factory, **refiner_extra_kwargs)
from pytential.qbx.utils import get_centers_on_side
discr_nodes = lpot_source.density_discr.nodes().get(queue)
fine_discr_nodes = \
lpot_source.quad_stage2_density_discr.nodes().get(queue)
int_centers = get_centers_on_side(lpot_source, -1)
int_centers = np.array([axis.get(queue) for axis in int_centers])
ext_centers = get_centers_on_side(lpot_source, +1)
ext_centers = np.array([axis.get(queue) for axis in ext_centers])
expansion_radii = lpot_source._expansion_radii("nsources").get(queue)
quad_res = lpot_source._coarsest_quad_resolution("npanels").get(queue)
source_danger_zone_radii = \
lpot_source._source_danger_zone_radii("npanels").get(queue)
# {{{ check if satisfying criteria
def check_disk_undisturbed_by_sources(centers_panel, sources_panel):
if centers_panel.element_nr == sources_panel.element_nr:
# Same panel
return
my_int_centers = int_centers[:, centers_panel.discr_slice]
my_ext_centers = ext_centers[:, centers_panel.discr_slice]
all_centers = np.append(my_int_centers, my_ext_centers, axis=-1)
nodes = discr_nodes[:, sources_panel.discr_slice]
# =distance(centers of panel 1, panel 2)
dist = (
la.norm((
all_centers[..., np.newaxis]
- nodes[:, np.newaxis, ...]).T,
axis=-1)
.min())
# Criterion:
# A center cannot be closer to another panel than to its originating
# panel.
rad = expansion_radii[centers_panel.discr_slice]
assert (dist >= rad * (1-expansion_disturbance_tolerance)).all(), \
(dist, rad, centers_panel.element_nr, sources_panel.element_nr)
def check_sufficient_quadrature_resolution(centers_panel, sources_panel):
dz_radius = source_danger_zone_radii[sources_panel.element_nr]
my_int_centers = int_centers[:, centers_panel.discr_slice]
my_ext_centers = ext_centers[:, centers_panel.discr_slice]
all_centers = np.append(my_int_centers, my_ext_centers, axis=-1)
nodes = fine_discr_nodes[:, sources_panel.discr_slice]
# =distance(centers of panel 1, panel 2)
dist = (
la.norm((
all_centers[..., np.newaxis]
- nodes[:, np.newaxis, ...]).T,
axis=-1)
.min())
# Criterion:
# The quadrature contribution from each panel is as accurate
# as from the center's own source panel.
assert dist >= dz_radius, \
(dist, dz_radius, centers_panel.element_nr, sources_panel.element_nr)
def check_quad_res_to_helmholtz_k_ratio(panel):
# Check wavenumber to panel size ratio.
assert quad_res[panel.element_nr] * helmholtz_k <= 5
for i, panel_1 in enumerate(iter_elements(lpot_source.density_discr)):
for panel_2 in iter_elements(lpot_source.density_discr):
check_disk_undisturbed_by_sources(panel_1, panel_2)
for panel_2 in iter_elements(lpot_source.quad_stage2_density_discr):
check_sufficient_quadrature_resolution(panel_1, panel_2)
if helmholtz_k is not None:
check_quad_res_to_helmholtz_k_ratio(panel_1)
def test_target_association(ctx_getter, curve_name, curve_f, nelements,
visualize=False):
cl_ctx = ctx_getter()
queue = cl.CommandQueue(cl_ctx)
# {{{ generate lpot source
order = 16
# Make the curve mesh.
mesh = make_curve_mesh(curve_f, np.linspace(0, 1, nelements+1), order)
from meshmode.discretization import Discretization
from meshmode.discretization.poly_element import \
InterpolatoryQuadratureSimplexGroupFactory
factory = InterpolatoryQuadratureSimplexGroupFactory(order)
discr = Discretization(cl_ctx, mesh, factory)
lpot_source, conn = QBXLayerPotentialSource(discr,
qbx_order=order, # not used in target association
fine_order=order).with_refinement()
del discr
from pytential.qbx.utils import get_interleaved_centers
centers = np.array([ax.get(queue)
for ax in get_interleaved_centers(queue, lpot_source)])
# }}}
# {{{ generate targets
from pyopencl.clrandom import PhiloxGenerator
rng = PhiloxGenerator(cl_ctx, seed=RNG_SEED)
nsources = lpot_source.density_discr.nnodes
noise = rng.uniform(queue, nsources, dtype=np.float, a=0.01, b=1.0)
tunnel_radius = \
lpot_source._close_target_tunnel_radius("nsources").with_queue(queue)
def targets_from_sources(sign, dist):
from pytential import sym, bind
dim = 2
nodes = bind(lpot_source.density_discr, sym.nodes(dim))(queue)
normals = bind(lpot_source.density_discr, sym.normal(dim))(queue)
return (nodes + normals * sign * dist).as_vector(np.object)
from pytential.target import PointsTarget
int_targets = PointsTarget(targets_from_sources(-1, noise * tunnel_radius))
ext_targets = PointsTarget(targets_from_sources(+1, noise * tunnel_radius))
far_targets = PointsTarget(targets_from_sources(+1, FAR_TARGET_DIST_FROM_SOURCE))
# Create target discretizations.
target_discrs = (
# On-surface targets, interior
(lpot_source.density_discr, -1),
# On-surface targets, exterior
(lpot_source.density_discr, +1),
# Interior close targets
(int_targets, -2),
# Exterior close targets
(ext_targets, +2),
# Far targets, should not need centers
(far_targets, 0),
)
sizes = np.cumsum([discr.nnodes for discr, _ in target_discrs])
(surf_int_slice,
surf_ext_slice,
vol_int_slice,
vol_ext_slice,
far_slice,
) = [slice(start, end) for start, end in zip(np.r_[0, sizes], sizes)]
# }}}
# {{{ run target associator and check
from pytential.qbx.target_assoc import (
TargetAssociationCodeContainer, associate_targets_to_qbx_centers)
from pytential.qbx.utils import TreeCodeContainer
code_container = TargetAssociationCodeContainer(
cl_ctx, TreeCodeContainer(cl_ctx))
target_assoc = (associate_targets_to_qbx_centers(
lpot_source,
code_container.get_wrangler(queue),
target_discrs,
target_association_tolerance=1e-10)
.get(queue=queue))
expansion_radii = lpot_source._expansion_radii("ncenters").get(queue)
surf_targets = np.array(
[axis.get(queue) for axis in lpot_source.density_discr.nodes()])
int_targets = np.array([axis.get(queue) for axis in int_targets.nodes()])
ext_targets = np.array([axis.get(queue) for axis in ext_targets.nodes()])
def visualize_curve_and_assoc():
import matplotlib.pyplot as plt
from meshmode.mesh.visualization import draw_curve
draw_curve(lpot_source.density_discr.mesh)
targets = int_targets
tgt_slice = surf_int_slice
plt.plot(centers[0], centers[1], "+", color="orange")
ax = plt.gca()
for tx, ty, tcenter in zip(
targets[0, tgt_slice],
targets[1, tgt_slice],
target_assoc.target_to_center[tgt_slice]):
if tcenter >= 0:
ax.add_artist(
plt.Line2D(
(tx, centers[0, tcenter]),
(ty, centers[1, tcenter]),
))
ax.set_aspect("equal")
plt.show()
if visualize:
visualize_curve_and_assoc()
# Checks that the targets match with centers on the appropriate side and
# within the allowable distance.
def check_close_targets(centers, targets, true_side,
target_to_center, target_to_side_result,
tgt_slice):
targets_have_centers = (target_to_center >= 0).all()
assert targets_have_centers
assert (target_to_side_result == true_side).all()
TOL = 1e-3
dists = la.norm((targets.T - centers.T[target_to_center]), axis=1)
assert (dists <= (1 + TOL) * expansion_radii[target_to_center]).all()
# Center side order = -1, 1, -1, 1, ...
target_to_center_side = 2 * (target_assoc.target_to_center % 2) - 1
# interior surface
check_close_targets(
centers, surf_targets, -1,
target_assoc.target_to_center[surf_int_slice],
target_to_center_side[surf_int_slice],
surf_int_slice)
# exterior surface
check_close_targets(
centers, surf_targets, +1,
target_assoc.target_to_center[surf_ext_slice],
target_to_center_side[surf_ext_slice],
surf_ext_slice)
# interior volume
check_close_targets(
centers, int_targets, -1,
target_assoc.target_to_center[vol_int_slice],
target_to_center_side[vol_int_slice],
vol_int_slice)
# exterior volume
check_close_targets(
centers, ext_targets, +1,
target_assoc.target_to_center[vol_ext_slice],
target_to_center_side[vol_ext_slice],
vol_ext_slice)
# Checks that far targets are not assigned a center.
assert (target_assoc.target_to_center[far_slice] == -1).all()