def get_sqrt_weight(self, dofdesc=None):
"""
:returns: the square root of :meth:`get_weight`.
"""
if self.use_l2_weighting:
return sym.sqrt_jac_q_weight(self.dim, dofdesc=dofdesc)
else:
return 1
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),
])
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
pt.plot(tang_deriv_from_src.real, label="src")
pt.legend()
pt.savefig(f"tangential-derivative-{resolution}", dpi=300)
rel_td_err_inf = la.norm(td_err, np.inf) / la.norm(
tang_deriv_ref, np.inf)
logger.info("rel_td_err_inf: %.5e" % rel_td_err_inf)
else:
rel_td_err_inf = None
# }}}
# {{{ any-D file plotting
if visualize:
sym_sqrt_j = sym.sqrt_jac_q_weight(ambient_dim)
u = bind(places, sym_u / sym_sqrt_j)(actx, u=weighted_u)
bdry_vis = make_visualizer(actx, density_discr, case.target_order + 3)
bdry_vis.write_vtk_file(f"integral-equation-source-{resolution}.vtu", [
("u", u),
("bc", bc),
])
try:
solved_pot = bind(places,
op.representation(sym_u),
auto_where=("qbx_target_tol", "plot_targets"))(
actx,
u=weighted_u,
**case.knl_concrete_kwargs)
def main(nelements):
import logging
logging.basicConfig(level=logging.INFO)
def get_obj_array(obj_array):
from pytools.obj_array import make_obj_array
return make_obj_array([
ary.get()
for ary in obj_array
])
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
from meshmode.mesh.generation import ( # noqa
make_curve_mesh, starfish, ellipse, drop)
mesh = make_curve_mesh(
lambda t: starfish(t),
np.linspace(0, 1, nelements+1),
target_order)
coarse_density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(target_order))
from pytential.qbx import QBXLayerPotentialSource
target_association_tolerance = 0.05
qbx, _ = QBXLayerPotentialSource(
coarse_density_discr, fine_order=ovsmp_target_order, qbx_order=qbx_order,
fmm_order=fmm_order,
target_association_tolerance=target_association_tolerance,
).with_refinement()
density_discr = qbx.density_discr
nodes = density_discr.nodes().with_queue(queue)
# Get normal vectors for the density discretization -- used in integration with stresslet
mv_normal = bind(density_discr, sym.normal(2))(queue)
normal = mv_normal.as_vector(np.object)
# {{{ describe bvp
from sumpy.kernel import LaplaceKernel
from pytential.symbolic.stokes import StressletWrapper
from pytools.obj_array import make_obj_array
dim=2
cse = sym.cse
nvec_sym = sym.make_sym_vector("normal", dim)
sigma_sym = sym.make_sym_vector("sigma", dim)
mu_sym = sym.var("mu")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym/sqrt_w)
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = -1
# Create stresslet object
stresslet_obj = StressletWrapper(dim=2)
# Describe boundary operator
bdry_op_sym = loc_sign * 0.5 * sigma_sym + sqrt_w * stresslet_obj.apply(inv_sqrt_w_sigma, nvec_sym, mu_sym, qbx_forced_limit='avg')
# Bind to the qbx discretization
bound_op = bind(qbx, bdry_op_sym)
# }}}
# {{{ fix rhs and solve
def fund_soln(x, y, loc):
#with direction (1,0) for point source
r = cl.clmath.sqrt((x - loc[0])**2 + (y - loc[1])**2)
scaling = 1./(4*np.pi*mu)
xcomp = (-cl.clmath.log(r) + (x - loc[0])**2/r**2) * scaling
ycomp = ((x - loc[0])*(y - loc[1])/r**2) * scaling
return [ xcomp, ycomp ]
def couette_soln(x, y, dp, h):
scaling = 1./(2*mu)
xcomp = scaling * dp * ((y+(h/2.))**2 - h * (y+(h/2.)))
ycomp = scaling * 0*y
return [xcomp, ycomp]
if soln_type == 'fundamental':
pt_loc = np.array([2.0, 0.0])
bc = fund_soln(nodes[0], nodes[1], pt_loc)
else:
dp = -10.
h = 2.5
bc = couette_soln(nodes[0], nodes[1], dp, h)
# Get rhs vector
bvp_rhs = bind(qbx, sqrt_w*sym.make_sym_vector("bc",dim))(queue, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(
bound_op.scipy_op(queue, "sigma", np.float64, mu=mu, normal=normal),
bvp_rhs, tol=1e-9, progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
sigma = gmres_result.solution
# Describe representation of solution for evaluation in domain
representation_sym = stresslet_obj.apply(inv_sqrt_w_sigma, nvec_sym, mu_sym, qbx_forced_limit=-2)
from sumpy.visualization import FieldPlotter
nsamp = 10
eval_points_1d = np.linspace(-1., 1., nsamp)
eval_points = np.zeros((2, len(eval_points_1d)**2))
eval_points[0,:] = np.tile(eval_points_1d, len(eval_points_1d))
eval_points[1,:] = np.repeat(eval_points_1d, len(eval_points_1d))
gamma_sym = sym.var("gamma")
inv_sqrt_w_gamma = cse(gamma_sym/sqrt_w)
constant_laplace_rep = sym.D(LaplaceKernel(dim=2), inv_sqrt_w_gamma, qbx_forced_limit=None)
sqrt_w_vec = bind(qbx, sqrt_w)(queue)
def general_mask(test_points):
const_density = bind((qbx, PointsTarget(test_points)), constant_laplace_rep)(queue, gamma=sqrt_w_vec).get()
return (abs(const_density) > 0.1)
def inside_domain(test_points):
mask = general_mask(test_points)
return np.array([
row[mask]
for row in test_points])
def stride_hack(arr):
from numpy.lib.stride_tricks import as_strided
return np.array(as_strided(arr, strides=(8 * len(arr[0]), 8)))
eval_points = inside_domain(eval_points)
eval_points_dev = cl.array.to_device(queue, eval_points)
# Evaluate the solution at the evaluation points
vel = bind(
(qbx, PointsTarget(eval_points_dev)),
representation_sym)(queue, sigma=sigma, mu=mu, normal=normal)
print("@@@@@@@@")
vel = get_obj_array(vel)
if soln_type == 'fundamental':
exact_soln = fund_soln(eval_points_dev[0], eval_points_dev[1], pt_loc)
else:
exact_soln = couette_soln(eval_points_dev[0], eval_points_dev[1], dp, h)
err = vel - get_obj_array(exact_soln)
print("@@@@@@@@")
print("L2 error estimate: ", np.sqrt((2./(nsamp-1))**2*np.sum(err[0]*err[0]) + (2./(nsamp-1))**2*np.sum(err[1]*err[1])))
max_error_loc = [abs(err[0]).argmax(), abs(err[1]).argmax()]
print("max error at sampled points: ", max(abs(err[0])), max(abs(err[1])))
print("exact velocity at max error points: x -> ", err[0][max_error_loc[0]], ", y -> ", err[1][max_error_loc[1]])
from pytential.symbolic.mappers import DerivativeTaker
rep_pressure = stresslet_obj.apply_pressure(inv_sqrt_w_sigma, nvec_sym, mu_sym, qbx_forced_limit=-2)
pressure = bind((qbx, PointsTarget(eval_points_dev)),
rep_pressure)(queue, sigma=sigma, mu=mu, normal=normal)
pressure = pressure.get()
print "pressure = ", pressure
x_dir_vecs = np.zeros((2,len(eval_points[0])))
x_dir_vecs[0,:] = 1.0
y_dir_vecs = np.zeros((2, len(eval_points[0])))
y_dir_vecs[1,:] = 1.0
x_dir_vecs = cl.array.to_device(queue, x_dir_vecs)
y_dir_vecs = cl.array.to_device(queue, y_dir_vecs)
dir_vec_sym = sym.make_sym_vector("force_direction", dim)
rep_stress = stresslet_obj.apply_stress(inv_sqrt_w_sigma, nvec_sym, dir_vec_sym, mu_sym, qbx_forced_limit=-2)
applied_stress_x = bind((qbx, PointsTarget(eval_points_dev)),
rep_stress)(queue, sigma=sigma, normal=normal, force_direction=x_dir_vecs, mu=mu)
applied_stress_x = get_obj_array(applied_stress_x)
applied_stress_y = bind((qbx, PointsTarget(eval_points_dev)),
rep_stress)(queue, sigma=sigma, normal=normal, force_direction=y_dir_vecs, mu=mu)
applied_stress_y = get_obj_array(applied_stress_y)
print "stress applied to x direction: ", applied_stress_x
print "stress applied to y direction: ", applied_stress_y
import matplotlib.pyplot as plt
plt.quiver(eval_points[0], eval_points[1], vel[0], vel[1], linewidth=0.1)
file_name = "field-n%s.pdf"%(nelements)
plt.savefig(file_name)
return (max(abs(err[0])), max(abs(err[1])))
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=np.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),
]
)
def get_bvp_error(lpot_source, fmm_order, qbx_order, k=0):
# This returns a tuple (err_l2, err_linf, nit).
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
assert k == 0 # Helmholtz would require a different representation
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")}
density_discr = lpot_source.density_discr
# {{{ find source and target points
source_angles = (np.pi / 2 +
np.linspace(0,
2 * np.pi * BVP_EXPERIMENT_N_ARMS,
BVP_EXPERIMENT_N_ARMS,
endpoint=False)) / BVP_EXPERIMENT_N_ARMS
source_points = 0.75 * np.array([
np.cos(source_angles),
np.sin(source_angles),
])
target_angles = (np.pi + np.pi / 2 +
np.linspace(0,
2 * np.pi * BVP_EXPERIMENT_N_ARMS,
BVP_EXPERIMENT_N_ARMS,
endpoint=False)) / BVP_EXPERIMENT_N_ARMS
target_points = 1.5 * np.array([
np.cos(target_angles),
np.sin(target_angles),
])
np.random.seed(17)
source_charges = np.random.randn(BVP_EXPERIMENT_N_ARMS)
source_points_dev = cl.array.to_device(queue, source_points)
target_points_dev = cl.array.to_device(queue, target_points)
source_charges_dev = cl.array.to_device(queue, source_charges)
from pytential.source import PointPotentialSource
from pytential.target import PointsTarget
point_source = PointPotentialSource(lpot_source.cl_context,
source_points_dev)
pot_src = sym.IntG(
# FIXME: qbx_forced_limit--really?
k_sym,
sym.var("charges"),
qbx_forced_limit=None,
**knl_kwargs)
ref_direct = bind((point_source, PointsTarget(target_points_dev)),
pot_src)(queue, charges=source_charges_dev,
**knl_kwargs).get()
sym_sqrt_j = sym.sqrt_jac_q_weight(density_discr.ambient_dim)
bc = bind((point_source, density_discr),
sym.normal_derivative(density_discr.ambient_dim,
pot_src,
where=sym.DEFAULT_TARGET))(
queue,
charges=source_charges_dev,
**knl_kwargs)
rhs = bind(density_discr, sym.var("bc") * sym_sqrt_j)(queue, bc=bc)
# }}}
# {{{ solve
bound_op = bind(
lpot_source,
-0.5 * sym.var("u") + sym_sqrt_j * sym.Sp(k_sym,
sym.var("u") / sym_sqrt_j,
qbx_forced_limit="avg",
**knl_kwargs))
from pytential.solve import gmres
gmres_result = gmres(bound_op.scipy_op(queue, "u", np.float64,
**knl_kwargs),
rhs,
tol=1e-10,
stall_iterations=100,
progress=True,
hard_failure=True)
u = gmres_result.solution
# }}}
points_target = PointsTarget(target_points_dev)
bound_tgt_op = bind((lpot_source, points_target),
sym.S(k_sym,
sym.var("u") / sym_sqrt_j,
qbx_forced_limit=None))
test_via_bdry = bound_tgt_op(queue, u=u).get()
err = ref_direct - test_via_bdry
err_l2 = la.norm(err, 2) / la.norm(ref_direct, 2)
err_linf = la.norm(err, np.inf) / la.norm(ref_direct, np.inf)
return err_l2, err_linf, gmres_result.iteration_count
print("rel_td_err_inf: %g" % rel_td_err_inf)
else:
rel_td_err_inf = None
# }}}
# {{{ any-D file plotting
if visualize:
bdry_vis = make_visualizer(queue, density_discr, case.target_order + 3)
bdry_normals = bind(density_discr, sym.normal(qbx.ambient_dim))(queue)\
.as_vector(dtype=object)
sym_sqrt_j = sym.sqrt_jac_q_weight(density_discr.ambient_dim)
u = bind(density_discr, sym.var("u") / sym_sqrt_j)(queue, u=weighted_u)
bdry_vis.write_vtk_file(
"source-%s.vtu" % resolution,
[
("u", u),
("bc", bc),
#("bdry_normals", bdry_normals),
])
from sumpy.visualization import make_field_plotter_from_bbox # noqa
from meshmode.mesh.processing import find_bounding_box
vis_grid_spacing = (0.1, 0.1, 0.1)[:qbx.ambient_dim]
if hasattr(case, "vis_grid_spacing"):
def timing_run(nx, ny):
import logging
logging.basicConfig(level=logging.WARNING) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
mesh = make_mesh(nx=nx, ny=ny)
density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (QBXLayerPotentialSource,
QBXTargetAssociationFailedException)
qbx = QBXLayerPotentialSource(density_discr,
fine_order=bdry_ovsmp_quad_order,
qbx_order=qbx_order,
fmm_order=fmm_order)
# {{{ describe bvp
from sumpy.kernel import HelmholtzKernel
kernel = HelmholtzKernel(2)
cse = sym.cse
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym / sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
bdry_op_sym = (-loc_sign * 0.5 * sigma_sym + sqrt_w *
(alpha * sym.S(kernel, inv_sqrt_w_sigma, k=sym.var("k")) -
sym.D(kernel, inv_sqrt_w_sigma, k=sym.var("k"))))
# }}}
bound_op = bind(qbx, bdry_op_sym)
# {{{ fix rhs and solve
mode_nr = 3
nodes = density_discr.nodes().with_queue(queue)
angle = cl.clmath.atan2(nodes[1], nodes[0])
sigma = cl.clmath.cos(mode_nr * angle)
# }}}
# {{{ postprocess/visualize
repr_kwargs = dict(k=sym.var("k"), qbx_forced_limit=+1)
sym_op = sym.S(kernel, sym.var("sigma"), **repr_kwargs)
bound_op = bind(qbx, sym_op)
print("FMM WARM-UP RUN 1: %d elements" % mesh.nelements)
bound_op(queue, sigma=sigma, k=k)
print("FMM WARM-UP RUN 2: %d elements" % mesh.nelements)
bound_op(queue, sigma=sigma, k=k)
queue.finish()
print("FMM TIMING RUN: %d elements" % mesh.nelements)
from time import time
t_start = time()
bound_op(queue, sigma=sigma, k=k)
queue.finish()
elapsed = time() - t_start
print("FMM TIMING RUN DONE: %d elements -> %g s" %
(mesh.nelements, elapsed))
return (mesh.nelements, elapsed)
if 0:
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=1500)
targets = cl.array.to_device(queue, fplot.points)
qbx_tgt_tol = qbx.copy(target_association_tolerance=0.05)
indicator_qbx = qbx_tgt_tol.copy(fmm_level_to_order=lambda lev: 7,
qbx_order=2)
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind((indicator_qbx, PointsTarget(targets)),
sym_op)(queue, sigma=ones_density).get()
qbx_stick_out = qbx.copy(target_stick_out_factor=0.1)
try:
fld_in_vol = bind((qbx_stick_out, PointsTarget(targets)),
sym_op)(queue, sigma=sigma, k=k).get()
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file(
"failed-targets.vts",
[("failed", e.failed_target_flags.get(queue))])
raise
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file("potential-scaling.vts",
[("potential", fld_in_vol),
("indicator", indicator)])
def timing_run(nx, ny):
import logging
logging.basicConfig(level=logging.WARNING) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
mesh = make_mesh(nx=nx, ny=ny)
density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (
QBXLayerPotentialSource, QBXTargetAssociationFailedException)
qbx = QBXLayerPotentialSource(
density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
fmm_order=fmm_order
)
# {{{ describe bvp
from sumpy.kernel import HelmholtzKernel
kernel = HelmholtzKernel(2)
cse = sym.cse
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym/sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
bdry_op_sym = (-loc_sign*0.5*sigma_sym
+ sqrt_w*(
alpha*sym.S(kernel, inv_sqrt_w_sigma, k=sym.var("k"))
- sym.D(kernel, inv_sqrt_w_sigma, k=sym.var("k"))
))
# }}}
bound_op = bind(qbx, bdry_op_sym)
# {{{ fix rhs and solve
mode_nr = 3
nodes = density_discr.nodes().with_queue(queue)
angle = cl.clmath.atan2(nodes[1], nodes[0])
sigma = cl.clmath.cos(mode_nr*angle)
# }}}
# {{{ postprocess/visualize
repr_kwargs = dict(k=sym.var("k"), qbx_forced_limit=+1)
sym_op = sym.S(kernel, sym.var("sigma"), **repr_kwargs)
bound_op = bind(qbx, sym_op)
print("FMM WARM-UP RUN 1: %d elements" % mesh.nelements)
bound_op(queue, sigma=sigma, k=k)
print("FMM WARM-UP RUN 2: %d elements" % mesh.nelements)
bound_op(queue, sigma=sigma, k=k)
queue.finish()
print("FMM TIMING RUN: %d elements" % mesh.nelements)
from time import time
t_start = time()
bound_op(queue, sigma=sigma, k=k)
queue.finish()
elapsed = time()-t_start
print("FMM TIMING RUN DONE: %d elements -> %g s"
% (mesh.nelements, elapsed))
return (mesh.nelements, elapsed)
if 0:
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=1500)
targets = cl.array.to_device(queue, fplot.points)
qbx_tgt_tol = qbx.copy(target_association_tolerance=0.05)
indicator_qbx = qbx_tgt_tol.copy(
fmm_level_to_order=lambda lev: 7, qbx_order=2)
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind(
(indicator_qbx, PointsTarget(targets)),
sym_op)(
queue, sigma=ones_density).get()
qbx_stick_out = qbx.copy(target_stick_out_factor=0.1)
try:
fld_in_vol = bind(
(qbx_stick_out, PointsTarget(targets)),
sym_op)(queue, sigma=sigma, k=k).get()
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file(
"failed-targets.vts",
[
("failed", e.failed_target_flags.get(queue))
]
)
raise
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file(
"potential-scaling.vts",
[
("potential", fld_in_vol),
("indicator", indicator)
]
)
def main():
import logging
logging.basicConfig(level=logging.INFO)
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))
from pytential.qbx import QBXLayerPotentialSource
qbx = QBXLayerPotentialSource(
density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
fmm_order=fmm_order
)
# {{{ describe bvp
from sumpy.kernel import HelmholtzKernel
kernel = HelmholtzKernel(2)
cse = sym.cse
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight()
inv_sqrt_w_sigma = cse(sigma_sym/sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = -1
bdry_op_sym = (-loc_sign*0.5*sigma_sym
+ sqrt_w*(
alpha*sym.S(kernel, inv_sqrt_w_sigma, k=sym.var("k"))
- sym.D(kernel, inv_sqrt_w_sigma, k=sym.var("k"))
))
# }}}
bound_op = bind(qbx, bdry_op_sym)
# {{{ fix rhs and solve
mode_nr = 3
nodes = density_discr.nodes().with_queue(queue)
angle = cl.clmath.atan2(nodes[1], nodes[0])
bc = cl.clmath.cos(mode_nr*angle)
bvp_rhs = bind(qbx, sqrt_w*sym.var("bc"))(queue, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(
bound_op.scipy_op(queue, "sigma", k=k),
bvp_rhs, tol=1e-14, progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
sigma = gmres_result.solution
representation_sym = (
alpha*sym.S(kernel, inv_sqrt_w_sigma, k=sym.var("k"))
- sym.D(kernel, inv_sqrt_w_sigma, k=sym.var("k")))
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=1500)
from pytential.target import PointsTarget
fld_in_vol = bind(
(qbx, PointsTarget(fplot.points)),
representation_sym)(queue, sigma=sigma, k=k).get()
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file(
"potential.vts",
[
("potential", fld_in_vol)
]
)
def test_build_matrix_conditioning(actx_factory,
side,
op_type,
visualize=False):
"""Checks that :math:`I + K`, where :math:`K` is compact gives a
well-conditioned operator when it should. For example, the exterior Laplace
problem has a nullspace, so we check that and remove it.
"""
actx = actx_factory()
# prevent cache explosion
from sympy.core.cache import clear_cache
clear_cache()
case = extra.CurveTestCase(
name="ellipse",
curve_fn=lambda t: ellipse(3.0, t),
target_order=16,
source_ovsmp=1,
qbx_order=4,
resolutions=[64],
op_type=op_type,
side=side,
)
logger.info("\n%s", case)
# {{{ geometry
qbx = case.get_layer_potential(actx, case.resolutions[-1],
case.target_order)
from pytential.qbx.refinement import refine_geometry_collection
places = GeometryCollection(qbx, auto_where=case.name)
places = refine_geometry_collection(
places, refine_discr_stage=sym.QBX_SOURCE_QUAD_STAGE2)
dd = places.auto_source.to_stage1()
density_discr = places.get_discretization(dd.geometry)
logger.info("nelements: %d", density_discr.mesh.nelements)
logger.info("ndofs: %d", density_discr.ndofs)
# }}}
# {{{ check matrix
from pytential.symbolic.execution import build_matrix
sym_u, sym_op = case.get_operator(places.ambient_dim,
qbx_forced_limit="avg")
mat = actx.to_numpy(
build_matrix(actx,
places,
sym_op,
sym_u,
context=case.knl_concrete_kwargs))
kappa = la.cond(mat)
_, sigma, _ = la.svd(mat)
logger.info("cond: %.5e sigma_max %.5e", kappa, sigma[0])
# NOTE: exterior Laplace has a nullspace
if side == +1 and op_type == "double":
assert kappa > 1.0e+9
assert sigma[-1] < 1.0e-9
else:
assert kappa < 1.0e+1
assert sigma[-1] > 1.0e-2
# remove the nullspace and check that it worked
if side == +1 and op_type == "double":
# NOTE: this adds the "mean" to remove the nullspace for the operator
# See `pytential.symbolic.pde.scalar` for the equivalent formulation
w = actx.to_numpy(
flatten(
bind(places,
sym.sqrt_jac_q_weight(places.ambient_dim)**2)(actx),
actx))
w = np.tile(w.reshape(-1, 1), w.size).T
kappa = la.cond(mat + w)
assert kappa < 1.0e+2
# }}}
# {{{ plot
if not visualize:
return
side = "int" if side == -1 else "ext"
import matplotlib.pyplot as plt
plt.imshow(mat)
plt.colorbar()
plt.title(fr"$\kappa(A) = {kappa:.5e}$")
plt.savefig(f"test_cond_{op_type}_{side}_mat")
plt.clf()
plt.plot(sigma)
plt.ylabel(r"$\sigma$")
plt.grid()
plt.savefig(f"test_cond_{op_type}_{side}_svd")
plt.clf()
def main():
import logging
logging.basicConfig(level=logging.WARNING) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
from meshmode.mesh.generation import ellipse, make_curve_mesh
from functools import partial
if 0:
mesh = make_curve_mesh(
partial(ellipse, 1),
np.linspace(0, 1, nelements+1),
mesh_order)
else:
base_mesh = make_curve_mesh(
partial(ellipse, 1),
np.linspace(0, 1, nelements+1),
mesh_order)
from meshmode.mesh.processing import affine_map, merge_disjoint_meshes
nx = 2
ny = 2
dx = 2 / nx
meshes = [
affine_map(
base_mesh,
A=np.diag([dx*0.25, dx*0.25]),
b=np.array([dx*(ix-nx/2), dx*(iy-ny/2)]))
for ix in range(nx)
for iy in range(ny)]
mesh = merge_disjoint_meshes(meshes, single_group=True)
if 0:
from meshmode.mesh.visualization import draw_curve
draw_curve(mesh)
import matplotlib.pyplot as plt
plt.show()
pre_density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (
QBXLayerPotentialSource, QBXTargetAssociationFailedException)
qbx, _ = QBXLayerPotentialSource(
pre_density_discr, fine_order=bdry_ovsmp_quad_order, qbx_order=qbx_order,
fmm_order=fmm_order
).with_refinement()
density_discr = qbx.density_discr
# {{{ describe bvp
from sumpy.kernel import LaplaceKernel, HelmholtzKernel
kernel = HelmholtzKernel(2)
cse = sym.cse
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym/sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
bdry_op_sym = (-loc_sign*0.5*sigma_sym
+ sqrt_w*(
alpha*sym.S(kernel, inv_sqrt_w_sigma, k=sym.var("k"),
qbx_forced_limit=+1)
- sym.D(kernel, inv_sqrt_w_sigma, k=sym.var("k"),
qbx_forced_limit="avg")
))
# }}}
bound_op = bind(qbx, bdry_op_sym)
# {{{ fix rhs and solve
nodes = density_discr.nodes().with_queue(queue)
k_vec = np.array([2, 1])
k_vec = k * k_vec / la.norm(k_vec, 2)
def u_incoming_func(x):
return cl.clmath.exp(
1j * (x[0] * k_vec[0] + x[1] * k_vec[1]))
bc = -u_incoming_func(nodes)
bvp_rhs = bind(qbx, sqrt_w*sym.var("bc"))(queue, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(
bound_op.scipy_op(queue, "sigma", dtype=np.complex128, k=k),
bvp_rhs, tol=1e-8, progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
sigma = gmres_result.solution
repr_kwargs = dict(k=sym.var("k"), qbx_forced_limit=None)
representation_sym = (
alpha*sym.S(kernel, inv_sqrt_w_sigma, **repr_kwargs)
- sym.D(kernel, inv_sqrt_w_sigma, **repr_kwargs))
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=500)
targets = cl.array.to_device(queue, fplot.points)
u_incoming = u_incoming_func(targets)
qbx_stick_out = qbx.copy(target_association_tolerance=0.05)
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind(
(qbx_stick_out, PointsTarget(targets)),
sym.D(LaplaceKernel(2), sym.var("sigma"), qbx_forced_limit=None))(
queue, sigma=ones_density).get()
try:
fld_in_vol = bind(
(qbx_stick_out, PointsTarget(targets)),
representation_sym)(queue, sigma=sigma, k=k).get()
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file(
"failed-targets.vts",
[
("failed", e.failed_target_flags.get(queue))
]
)
raise
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file(
"potential-helm.vts",
[
("potential", fld_in_vol),
("indicator", indicator),
("u_incoming", u_incoming.get()),
]
)
def main(nelements):
import logging
logging.basicConfig(level=logging.INFO)
def get_obj_array(obj_array):
from pytools.obj_array import make_obj_array
return make_obj_array([ary.get() for ary in obj_array])
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
from meshmode.mesh.generation import ( # noqa
make_curve_mesh, starfish, ellipse, drop)
mesh = make_curve_mesh(lambda t: starfish(t),
np.linspace(0, 1, nelements + 1), target_order)
coarse_density_discr = Discretization(
cl_ctx, mesh, InterpolatoryQuadratureSimplexGroupFactory(target_order))
from pytential.qbx import QBXLayerPotentialSource
target_association_tolerance = 0.05
qbx, _ = QBXLayerPotentialSource(
coarse_density_discr,
fine_order=ovsmp_target_order,
qbx_order=qbx_order,
fmm_order=fmm_order,
target_association_tolerance=target_association_tolerance,
).with_refinement()
density_discr = qbx.density_discr
nodes = density_discr.nodes().with_queue(queue)
# Get normal vectors for the density discretization -- used in integration with stresslet
mv_normal = bind(density_discr, sym.normal(2))(queue)
normal = mv_normal.as_vector(np.object)
# {{{ describe bvp
from sumpy.kernel import LaplaceKernel
from pytential.symbolic.stokes import StressletWrapper
from pytools.obj_array import make_obj_array
dim = 2
cse = sym.cse
nvec_sym = sym.make_sym_vector("normal", dim)
sigma_sym = sym.make_sym_vector("sigma", dim)
mu_sym = sym.var("mu")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym / sqrt_w)
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = -1
# Create stresslet object
stresslet_obj = StressletWrapper(dim=2)
# Describe boundary operator
bdry_op_sym = loc_sign * 0.5 * sigma_sym + sqrt_w * stresslet_obj.apply(
inv_sqrt_w_sigma, nvec_sym, mu_sym, qbx_forced_limit='avg')
# Bind to the qbx discretization
bound_op = bind(qbx, bdry_op_sym)
# }}}
# {{{ fix rhs and solve
def fund_soln(x, y, loc):
#with direction (1,0) for point source
r = cl.clmath.sqrt((x - loc[0])**2 + (y - loc[1])**2)
scaling = 1. / (4 * np.pi * mu)
xcomp = (-cl.clmath.log(r) + (x - loc[0])**2 / r**2) * scaling
ycomp = ((x - loc[0]) * (y - loc[1]) / r**2) * scaling
return [xcomp, ycomp]
def couette_soln(x, y, dp, h):
scaling = 1. / (2 * mu)
xcomp = scaling * dp * ((y + (h / 2.))**2 - h * (y + (h / 2.)))
ycomp = scaling * 0 * y
return [xcomp, ycomp]
if soln_type == 'fundamental':
pt_loc = np.array([2.0, 0.0])
bc = fund_soln(nodes[0], nodes[1], pt_loc)
else:
dp = -10.
h = 2.5
bc = couette_soln(nodes[0], nodes[1], dp, h)
# Get rhs vector
bvp_rhs = bind(qbx, sqrt_w * sym.make_sym_vector("bc", dim))(queue, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(bound_op.scipy_op(queue,
"sigma",
np.float64,
mu=mu,
normal=normal),
bvp_rhs,
tol=1e-9,
progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
sigma = gmres_result.solution
# Describe representation of solution for evaluation in domain
representation_sym = stresslet_obj.apply(inv_sqrt_w_sigma,
nvec_sym,
mu_sym,
qbx_forced_limit=-2)
from sumpy.visualization import FieldPlotter
nsamp = 10
eval_points_1d = np.linspace(-1., 1., nsamp)
eval_points = np.zeros((2, len(eval_points_1d)**2))
eval_points[0, :] = np.tile(eval_points_1d, len(eval_points_1d))
eval_points[1, :] = np.repeat(eval_points_1d, len(eval_points_1d))
gamma_sym = sym.var("gamma")
inv_sqrt_w_gamma = cse(gamma_sym / sqrt_w)
constant_laplace_rep = sym.D(LaplaceKernel(dim=2),
inv_sqrt_w_gamma,
qbx_forced_limit=None)
sqrt_w_vec = bind(qbx, sqrt_w)(queue)
def general_mask(test_points):
const_density = bind((qbx, PointsTarget(test_points)),
constant_laplace_rep)(queue,
gamma=sqrt_w_vec).get()
return (abs(const_density) > 0.1)
def inside_domain(test_points):
mask = general_mask(test_points)
return np.array([row[mask] for row in test_points])
def stride_hack(arr):
from numpy.lib.stride_tricks import as_strided
return np.array(as_strided(arr, strides=(8 * len(arr[0]), 8)))
eval_points = inside_domain(eval_points)
eval_points_dev = cl.array.to_device(queue, eval_points)
# Evaluate the solution at the evaluation points
vel = bind((qbx, PointsTarget(eval_points_dev)),
representation_sym)(queue, sigma=sigma, mu=mu, normal=normal)
print("@@@@@@@@")
vel = get_obj_array(vel)
if soln_type == 'fundamental':
exact_soln = fund_soln(eval_points_dev[0], eval_points_dev[1], pt_loc)
else:
exact_soln = couette_soln(eval_points_dev[0], eval_points_dev[1], dp,
h)
err = vel - get_obj_array(exact_soln)
print("@@@@@@@@")
print(
"L2 error estimate: ",
np.sqrt((2. / (nsamp - 1))**2 * np.sum(err[0] * err[0]) +
(2. / (nsamp - 1))**2 * np.sum(err[1] * err[1])))
max_error_loc = [abs(err[0]).argmax(), abs(err[1]).argmax()]
print("max error at sampled points: ", max(abs(err[0])), max(abs(err[1])))
print("exact velocity at max error points: x -> ",
err[0][max_error_loc[0]], ", y -> ", err[1][max_error_loc[1]])
from pytential.symbolic.mappers import DerivativeTaker
rep_pressure = stresslet_obj.apply_pressure(inv_sqrt_w_sigma,
nvec_sym,
mu_sym,
qbx_forced_limit=-2)
pressure = bind((qbx, PointsTarget(eval_points_dev)),
rep_pressure)(queue, sigma=sigma, mu=mu, normal=normal)
pressure = pressure.get()
print "pressure = ", pressure
x_dir_vecs = np.zeros((2, len(eval_points[0])))
x_dir_vecs[0, :] = 1.0
y_dir_vecs = np.zeros((2, len(eval_points[0])))
y_dir_vecs[1, :] = 1.0
x_dir_vecs = cl.array.to_device(queue, x_dir_vecs)
y_dir_vecs = cl.array.to_device(queue, y_dir_vecs)
dir_vec_sym = sym.make_sym_vector("force_direction", dim)
rep_stress = stresslet_obj.apply_stress(inv_sqrt_w_sigma,
nvec_sym,
dir_vec_sym,
mu_sym,
qbx_forced_limit=-2)
applied_stress_x = bind((qbx, PointsTarget(eval_points_dev)),
rep_stress)(queue,
sigma=sigma,
normal=normal,
force_direction=x_dir_vecs,
mu=mu)
applied_stress_x = get_obj_array(applied_stress_x)
applied_stress_y = bind((qbx, PointsTarget(eval_points_dev)),
rep_stress)(queue,
sigma=sigma,
normal=normal,
force_direction=y_dir_vecs,
mu=mu)
applied_stress_y = get_obj_array(applied_stress_y)
print "stress applied to x direction: ", applied_stress_x
print "stress applied to y direction: ", applied_stress_y
import matplotlib.pyplot as plt
plt.quiver(eval_points[0], eval_points[1], vel[0], vel[1], linewidth=0.1)
file_name = "field-n%s.pdf" % (nelements)
plt.savefig(file_name)
return (max(abs(err[0])), max(abs(err[1])))
def timing_run(nx, ny, visualize=False):
import logging
logging.basicConfig(level=logging.WARNING) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
actx = PyOpenCLArrayContext(queue)
mesh = make_mesh(nx=nx, ny=ny, visualize=visualize)
density_discr = Discretization(
actx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (QBXLayerPotentialSource,
QBXTargetAssociationFailedException)
qbx = QBXLayerPotentialSource(density_discr,
fine_order=bdry_ovsmp_quad_order,
qbx_order=qbx_order,
fmm_order=fmm_order)
places = {"qbx": qbx}
if visualize:
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=1500)
targets = PointsTarget(actx.from_numpy(fplot.points))
places.update({
"plot-targets":
targets,
"qbx-indicator":
qbx.copy(target_association_tolerance=0.05,
fmm_level_to_order=lambda lev: 7,
qbx_order=2),
"qbx-target-assoc":
qbx.copy(target_association_tolerance=0.1)
})
from pytential import GeometryCollection
places = GeometryCollection(places, auto_where="qbx")
density_discr = places.get_discretization("qbx")
# {{{ describe bvp
from sumpy.kernel import HelmholtzKernel
kernel = HelmholtzKernel(2)
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = sym.cse(sigma_sym / sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
k_sym = sym.var("k")
S_sym = sym.S(kernel, inv_sqrt_w_sigma, k=k_sym, qbx_forced_limit=+1)
D_sym = sym.D(kernel, inv_sqrt_w_sigma, k=k_sym, qbx_forced_limit="avg")
bdry_op_sym = -loc_sign * 0.5 * sigma_sym + sqrt_w * (alpha * S_sym +
D_sym)
# }}}
bound_op = bind(places, bdry_op_sym)
# {{{ fix rhs and solve
mode_nr = 3
from meshmode.dof_array import thaw
nodes = thaw(actx, density_discr.nodes())
angle = actx.np.arctan2(nodes[1], nodes[0])
sigma = actx.np.cos(mode_nr * angle)
# }}}
# {{{ postprocess/visualize
repr_kwargs = dict(k=sym.var("k"), qbx_forced_limit=+1)
sym_op = sym.S(kernel, sym.var("sigma"), **repr_kwargs)
bound_op = bind(places, sym_op)
print("FMM WARM-UP RUN 1: %5d elements" % mesh.nelements)
bound_op(actx, sigma=sigma, k=k)
queue.finish()
print("FMM WARM-UP RUN 2: %5d elements" % mesh.nelements)
bound_op(actx, sigma=sigma, k=k)
queue.finish()
from time import time
t_start = time()
bound_op(actx, sigma=sigma, k=k)
actx.queue.finish()
elapsed = time() - t_start
print("FMM TIMING RUN: %5d elements -> %g s" %
(mesh.nelements, elapsed))
if visualize:
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind(places,
sym_op,
auto_where=("qbx-indicator", "plot-targets"))(
queue, sigma=ones_density).get()
try:
fld_in_vol = bind(places,
sym_op,
auto_where=("qbx-target-assoc",
"plot-targets"))(queue,
sigma=sigma,
k=k).get()
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file("scaling-study-failed-targets.vts", [
("failed", e.failed_target_flags.get(queue)),
])
raise
fplot.write_vtk_file("scaling-study-potential.vts", [
("potential", fld_in_vol),
("indicator", indicator),
])
return (mesh.nelements, elapsed)
def main(mesh_name="ellipse", visualize=False):
import logging
logging.basicConfig(level=logging.INFO) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
actx = PyOpenCLArrayContext(queue)
from meshmode.mesh.generation import ellipse, make_curve_mesh
from functools import partial
if mesh_name == "ellipse":
mesh = make_curve_mesh(partial(ellipse, 1),
np.linspace(0, 1, nelements + 1), mesh_order)
elif mesh_name == "ellipse_array":
base_mesh = make_curve_mesh(partial(ellipse, 1),
np.linspace(0, 1, nelements + 1),
mesh_order)
from meshmode.mesh.processing import affine_map, merge_disjoint_meshes
nx = 2
ny = 2
dx = 2 / nx
meshes = [
affine_map(base_mesh,
A=np.diag([dx * 0.25, dx * 0.25]),
b=np.array([dx * (ix - nx / 2), dx * (iy - ny / 2)]))
for ix in range(nx) for iy in range(ny)
]
mesh = merge_disjoint_meshes(meshes, single_group=True)
if visualize:
from meshmode.mesh.visualization import draw_curve
draw_curve(mesh)
import matplotlib.pyplot as plt
plt.show()
else:
raise ValueError(f"unknown mesh name: {mesh_name}")
pre_density_discr = Discretization(
actx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (QBXLayerPotentialSource,
QBXTargetAssociationFailedException)
qbx = QBXLayerPotentialSource(pre_density_discr,
fine_order=bdry_ovsmp_quad_order,
qbx_order=qbx_order,
fmm_order=fmm_order)
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=500)
targets = actx.from_numpy(fplot.points)
from pytential import GeometryCollection
places = GeometryCollection(
{
"qbx":
qbx,
"qbx_high_target_assoc_tol":
qbx.copy(target_association_tolerance=0.05),
"targets":
PointsTarget(targets)
},
auto_where="qbx")
density_discr = places.get_discretization("qbx")
# {{{ describe bvp
from sumpy.kernel import LaplaceKernel, HelmholtzKernel
kernel = HelmholtzKernel(2)
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = sym.cse(sigma_sym / sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
k_sym = sym.var("k")
bdry_op_sym = (
-loc_sign * 0.5 * sigma_sym + sqrt_w *
(alpha * sym.S(kernel, inv_sqrt_w_sigma, k=k_sym, qbx_forced_limit=+1)
- sym.D(kernel, inv_sqrt_w_sigma, k=k_sym, qbx_forced_limit="avg")))
# }}}
bound_op = bind(places, bdry_op_sym)
# {{{ fix rhs and solve
from meshmode.dof_array import thaw
nodes = thaw(actx, density_discr.nodes())
k_vec = np.array([2, 1])
k_vec = k * k_vec / la.norm(k_vec, 2)
def u_incoming_func(x):
return actx.np.exp(1j * (x[0] * k_vec[0] + x[1] * k_vec[1]))
bc = -u_incoming_func(nodes)
bvp_rhs = bind(places, sqrt_w * sym.var("bc"))(actx, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(bound_op.scipy_op(actx,
sigma_sym.name,
dtype=np.complex128,
k=k),
bvp_rhs,
tol=1e-8,
progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
repr_kwargs = dict(source="qbx_high_target_assoc_tol",
target="targets",
qbx_forced_limit=None)
representation_sym = (
alpha * sym.S(kernel, inv_sqrt_w_sigma, k=k_sym, **repr_kwargs) -
sym.D(kernel, inv_sqrt_w_sigma, k=k_sym, **repr_kwargs))
u_incoming = u_incoming_func(targets)
ones_density = density_discr.zeros(actx)
for elem in ones_density:
elem.fill(1)
indicator = actx.to_numpy(
bind(places, sym.D(LaplaceKernel(2), sigma_sym,
**repr_kwargs))(actx, sigma=ones_density))
try:
fld_in_vol = actx.to_numpy(
bind(places, representation_sym)(actx,
sigma=gmres_result.solution,
k=k))
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file("helmholtz-dirichlet-failed-targets.vts",
[("failed", e.failed_target_flags.get(queue))])
raise
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file("helmholtz-dirichlet-potential.vts", [
("potential", fld_in_vol),
("indicator", indicator),
("u_incoming", actx.to_numpy(u_incoming)),
])
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
def run_int_eq_test(cl_ctx, queue, case, resolution, visualize):
mesh = case.get_mesh(resolution, case.target_order)
print("%d elements" % mesh.nelements)
from pytential.qbx import QBXLayerPotentialSource
from meshmode.discretization import Discretization
from meshmode.discretization.poly_element import \
InterpolatoryQuadratureSimplexGroupFactory
pre_density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(case.target_order))
source_order = 4*case.target_order
refiner_extra_kwargs = {}
qbx_lpot_kwargs = {}
if case.fmm_backend is None:
qbx_lpot_kwargs["fmm_order"] = False
else:
if hasattr(case, "fmm_tol"):
from sumpy.expansion.level_to_order import SimpleExpansionOrderFinder
qbx_lpot_kwargs["fmm_level_to_order"] = SimpleExpansionOrderFinder(
case.fmm_tol)
elif hasattr(case, "fmm_order"):
qbx_lpot_kwargs["fmm_order"] = case.fmm_order
else:
qbx_lpot_kwargs["fmm_order"] = case.qbx_order + 5
qbx = QBXLayerPotentialSource(
pre_density_discr,
fine_order=source_order,
qbx_order=case.qbx_order,
_box_extent_norm=getattr(case, "box_extent_norm", None),
_from_sep_smaller_crit=getattr(case, "from_sep_smaller_crit", None),
_from_sep_smaller_min_nsources_cumul=30,
fmm_backend=case.fmm_backend, **qbx_lpot_kwargs)
if case.use_refinement:
if case.k != 0 and getattr(case, "refine_on_helmholtz_k", True):
refiner_extra_kwargs["kernel_length_scale"] = 5/case.k
if hasattr(case, "scaled_max_curvature_threshold"):
refiner_extra_kwargs["_scaled_max_curvature_threshold"] = \
case.scaled_max_curvature_threshold
if hasattr(case, "expansion_disturbance_tolerance"):
refiner_extra_kwargs["_expansion_disturbance_tolerance"] = \
case.expansion_disturbance_tolerance
if hasattr(case, "refinement_maxiter"):
refiner_extra_kwargs["maxiter"] = case.refinement_maxiter
#refiner_extra_kwargs["visualize"] = True
print("%d elements before refinement" % pre_density_discr.mesh.nelements)
qbx, _ = qbx.with_refinement(**refiner_extra_kwargs)
print("%d stage-1 elements after refinement"
% qbx.density_discr.mesh.nelements)
print("%d stage-2 elements after refinement"
% qbx.stage2_density_discr.mesh.nelements)
print("quad stage-2 elements have %d nodes"
% qbx.quad_stage2_density_discr.groups[0].nunit_nodes)
density_discr = qbx.density_discr
if hasattr(case, "visualize_geometry") and case.visualize_geometry:
bdry_normals = bind(
density_discr, sym.normal(mesh.ambient_dim)
)(queue).as_vector(dtype=object)
bdry_vis = make_visualizer(queue, density_discr, case.target_order)
bdry_vis.write_vtk_file("geometry.vtu", [
("normals", bdry_normals)
])
# {{{ plot geometry
if 0:
if mesh.ambient_dim == 2:
# show geometry, centers, normals
nodes_h = density_discr.nodes().get(queue=queue)
pt.plot(nodes_h[0], nodes_h[1], "x-")
normal = bind(density_discr, sym.normal(2))(queue).as_vector(np.object)
pt.quiver(nodes_h[0], nodes_h[1],
normal[0].get(queue), normal[1].get(queue))
pt.gca().set_aspect("equal")
pt.show()
elif mesh.ambient_dim == 3:
bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)
bdry_normals = bind(density_discr, sym.normal(3))(queue)\
.as_vector(dtype=object)
bdry_vis.write_vtk_file("pre-solve-source-%s.vtu" % resolution, [
("bdry_normals", bdry_normals),
])
else:
raise ValueError("invalid mesh dim")
# }}}
# {{{ set up operator
from pytential.symbolic.pde.scalar import (
DirichletOperator,
NeumannOperator)
from sumpy.kernel import LaplaceKernel, HelmholtzKernel
if case.k:
knl = HelmholtzKernel(mesh.ambient_dim)
knl_kwargs = {"k": sym.var("k")}
concrete_knl_kwargs = {"k": case.k}
else:
knl = LaplaceKernel(mesh.ambient_dim)
knl_kwargs = {}
concrete_knl_kwargs = {}
if knl.is_complex_valued:
dtype = np.complex128
else:
dtype = np.float64
loc_sign = +1 if case.prob_side in [+1, "scat"] else -1
if case.bc_type == "dirichlet":
op = DirichletOperator(knl, loc_sign, use_l2_weighting=True,
kernel_arguments=knl_kwargs)
elif case.bc_type == "neumann":
op = NeumannOperator(knl, loc_sign, use_l2_weighting=True,
use_improved_operator=False, kernel_arguments=knl_kwargs)
else:
assert False
op_u = op.operator(sym.var("u"))
# }}}
# {{{ set up test data
if case.prob_side == -1:
test_src_geo_radius = case.outer_radius
test_tgt_geo_radius = case.inner_radius
elif case.prob_side == +1:
test_src_geo_radius = case.inner_radius
test_tgt_geo_radius = case.outer_radius
elif case.prob_side == "scat":
test_src_geo_radius = case.outer_radius
test_tgt_geo_radius = case.outer_radius
else:
raise ValueError("unknown problem_side")
point_sources = make_circular_point_group(
mesh.ambient_dim, 10, test_src_geo_radius,
func=lambda x: x**1.5)
test_targets = make_circular_point_group(
mesh.ambient_dim, 20, test_tgt_geo_radius)
np.random.seed(22)
source_charges = np.random.randn(point_sources.shape[1])
source_charges[-1] = -np.sum(source_charges[:-1])
source_charges = source_charges.astype(dtype)
assert np.sum(source_charges) < 1e-15
source_charges_dev = cl.array.to_device(queue, source_charges)
# }}}
# {{{ establish BCs
from pytential.source import PointPotentialSource
from pytential.target import PointsTarget
point_source = PointPotentialSource(cl_ctx, point_sources)
pot_src = sym.IntG(
# FIXME: qbx_forced_limit--really?
knl, sym.var("charges"), qbx_forced_limit=None, **knl_kwargs)
test_direct = bind((point_source, PointsTarget(test_targets)), pot_src)(
queue, charges=source_charges_dev, **concrete_knl_kwargs)
if case.bc_type == "dirichlet":
bc = bind((point_source, density_discr), pot_src)(
queue, charges=source_charges_dev, **concrete_knl_kwargs)
elif case.bc_type == "neumann":
bc = bind(
(point_source, density_discr),
sym.normal_derivative(
qbx.ambient_dim, pot_src, where=sym.DEFAULT_TARGET)
)(queue, charges=source_charges_dev, **concrete_knl_kwargs)
# }}}
# {{{ solve
bound_op = bind(qbx, op_u)
rhs = bind(density_discr, op.prepare_rhs(sym.var("bc")))(queue, bc=bc)
try:
from pytential.solve import gmres
gmres_result = gmres(
bound_op.scipy_op(queue, "u", dtype, **concrete_knl_kwargs),
rhs,
tol=case.gmres_tol,
progress=True,
hard_failure=True,
stall_iterations=50, no_progress_factor=1.05)
except QBXTargetAssociationFailedException as e:
bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)
bdry_vis.write_vtk_file("failed-targets-%s.vtu" % resolution, [
("failed_targets", e.failed_target_flags),
])
raise
print("gmres state:", gmres_result.state)
weighted_u = gmres_result.solution
# }}}
# {{{ build matrix for spectrum check
if 0:
from sumpy.tools import build_matrix
mat = build_matrix(
bound_op.scipy_op(
queue, arg_name="u", dtype=dtype, k=case.k))
w, v = la.eig(mat)
if 0:
pt.imshow(np.log10(1e-20+np.abs(mat)))
pt.colorbar()
pt.show()
#assert abs(s[-1]) < 1e-13, "h
#assert abs(s[-2]) > 1e-7
#from pudb import set_trace; set_trace()
# }}}
if case.prob_side != "scat":
# {{{ error check
points_target = PointsTarget(test_targets)
bound_tgt_op = bind((qbx, points_target),
op.representation(sym.var("u")))
test_via_bdry = bound_tgt_op(queue, u=weighted_u, k=case.k)
err = test_via_bdry - test_direct
err = err.get()
test_direct = test_direct.get()
test_via_bdry = test_via_bdry.get()
# {{{ remove effect of net source charge
if case.k == 0 and case.bc_type == "neumann" and loc_sign == -1:
# remove constant offset in interior Laplace Neumann error
tgt_ones = np.ones_like(test_direct)
tgt_ones = tgt_ones/la.norm(tgt_ones)
err = err - np.vdot(tgt_ones, err)*tgt_ones
# }}}
rel_err_2 = la.norm(err)/la.norm(test_direct)
rel_err_inf = la.norm(err, np.inf)/la.norm(test_direct, np.inf)
# }}}
print("rel_err_2: %g rel_err_inf: %g" % (rel_err_2, rel_err_inf))
else:
rel_err_2 = None
rel_err_inf = None
# {{{ test gradient
if case.check_gradient and case.prob_side != "scat":
bound_grad_op = bind((qbx, points_target),
op.representation(
sym.var("u"),
map_potentials=lambda pot: sym.grad(mesh.ambient_dim, pot),
qbx_forced_limit=None))
#print(bound_t_deriv_op.code)
grad_from_src = bound_grad_op(
queue, u=weighted_u, **concrete_knl_kwargs)
grad_ref = (bind(
(point_source, points_target),
sym.grad(mesh.ambient_dim, pot_src)
)(queue, charges=source_charges_dev, **concrete_knl_kwargs)
)
grad_err = (grad_from_src - grad_ref)
rel_grad_err_inf = (
la.norm(grad_err[0].get(), np.inf)
/ la.norm(grad_ref[0].get(), np.inf))
print("rel_grad_err_inf: %g" % rel_grad_err_inf)
# }}}
# {{{ test tangential derivative
if case.check_tangential_deriv and case.prob_side != "scat":
bound_t_deriv_op = bind(qbx,
op.representation(
sym.var("u"),
map_potentials=lambda pot: sym.tangential_derivative(2, pot),
qbx_forced_limit=loc_sign))
#print(bound_t_deriv_op.code)
tang_deriv_from_src = bound_t_deriv_op(
queue, u=weighted_u, **concrete_knl_kwargs).as_scalar().get()
tang_deriv_ref = (bind(
(point_source, density_discr),
sym.tangential_derivative(2, pot_src)
)(queue, charges=source_charges_dev, **concrete_knl_kwargs)
.as_scalar().get())
if 0:
pt.plot(tang_deriv_ref.real)
pt.plot(tang_deriv_from_src.real)
pt.show()
td_err = (tang_deriv_from_src - tang_deriv_ref)
rel_td_err_inf = la.norm(td_err, np.inf)/la.norm(tang_deriv_ref, np.inf)
print("rel_td_err_inf: %g" % rel_td_err_inf)
else:
rel_td_err_inf = None
# }}}
# {{{ any-D file plotting
if visualize:
bdry_vis = make_visualizer(queue, density_discr, case.target_order+3)
bdry_normals = bind(density_discr, sym.normal(qbx.ambient_dim))(queue)\
.as_vector(dtype=object)
sym_sqrt_j = sym.sqrt_jac_q_weight(density_discr.ambient_dim)
u = bind(density_discr, sym.var("u")/sym_sqrt_j)(queue, u=weighted_u)
bdry_vis.write_vtk_file("source-%s.vtu" % resolution, [
("u", u),
("bc", bc),
#("bdry_normals", bdry_normals),
])
from sumpy.visualization import make_field_plotter_from_bbox # noqa
from meshmode.mesh.processing import find_bounding_box
vis_grid_spacing = (0.1, 0.1, 0.1)[:qbx.ambient_dim]
if hasattr(case, "vis_grid_spacing"):
vis_grid_spacing = case.vis_grid_spacing
vis_extend_factor = 0.2
if hasattr(case, "vis_extend_factor"):
vis_grid_spacing = case.vis_grid_spacing
fplot = make_field_plotter_from_bbox(
find_bounding_box(mesh),
h=vis_grid_spacing,
extend_factor=vis_extend_factor)
qbx_tgt_tol = qbx.copy(target_association_tolerance=0.15)
from pytential.target import PointsTarget
try:
solved_pot = bind(
(qbx_tgt_tol, PointsTarget(fplot.points)),
op.representation(sym.var("u"))
)(queue, u=weighted_u, k=case.k)
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file(
"failed-targets.vts",
[
("failed_targets", e.failed_target_flags.get(queue))
])
raise
from sumpy.kernel import LaplaceKernel
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind(
(qbx_tgt_tol, PointsTarget(fplot.points)),
-sym.D(LaplaceKernel(density_discr.ambient_dim),
sym.var("sigma"),
qbx_forced_limit=None))(
queue, sigma=ones_density).get()
solved_pot = solved_pot.get()
true_pot = bind((point_source, PointsTarget(fplot.points)), pot_src)(
queue, charges=source_charges_dev, **concrete_knl_kwargs).get()
#fplot.show_scalar_in_mayavi(solved_pot.real, max_val=5)
if case.prob_side == "scat":
fplot.write_vtk_file(
"potential-%s.vts" % resolution,
[
("pot_scattered", solved_pot),
("pot_incoming", -true_pot),
("indicator", indicator),
]
)
else:
fplot.write_vtk_file(
"potential-%s.vts" % resolution,
[
("solved_pot", solved_pot),
("true_pot", true_pot),
("indicator", indicator),
]
)
# }}}
class Result(Record):
pass
return Result(
h_max=qbx.h_max,
rel_err_2=rel_err_2,
rel_err_inf=rel_err_inf,
rel_td_err_inf=rel_td_err_inf,
gmres_result=gmres_result)
def main():
import logging
logging.basicConfig(level=logging.WARNING) # INFO for more progress info
cl_ctx = cl.create_some_context()
queue = cl.CommandQueue(cl_ctx)
from meshmode.mesh.generation import ellipse, make_curve_mesh
from functools import partial
if 0:
mesh = make_curve_mesh(partial(ellipse, 1),
np.linspace(0, 1, nelements + 1), mesh_order)
else:
base_mesh = make_curve_mesh(partial(ellipse, 1),
np.linspace(0, 1, nelements + 1),
mesh_order)
from meshmode.mesh.processing import affine_map, merge_disjoint_meshes
nx = 2
ny = 2
dx = 2 / nx
meshes = [
affine_map(base_mesh,
A=np.diag([dx * 0.25, dx * 0.25]),
b=np.array([dx * (ix - nx / 2), dx * (iy - ny / 2)]))
for ix in range(nx) for iy in range(ny)
]
mesh = merge_disjoint_meshes(meshes, single_group=True)
if 0:
from meshmode.mesh.visualization import draw_curve
draw_curve(mesh)
import matplotlib.pyplot as plt
plt.show()
pre_density_discr = Discretization(
cl_ctx, mesh,
InterpolatoryQuadratureSimplexGroupFactory(bdry_quad_order))
from pytential.qbx import (QBXLayerPotentialSource,
QBXTargetAssociationFailedException)
qbx, _ = QBXLayerPotentialSource(pre_density_discr,
fine_order=bdry_ovsmp_quad_order,
qbx_order=qbx_order,
fmm_order=fmm_order).with_refinement()
density_discr = qbx.density_discr
# {{{ describe bvp
from sumpy.kernel import LaplaceKernel, HelmholtzKernel
kernel = HelmholtzKernel(2)
cse = sym.cse
sigma_sym = sym.var("sigma")
sqrt_w = sym.sqrt_jac_q_weight(2)
inv_sqrt_w_sigma = cse(sigma_sym / sqrt_w)
# Brakhage-Werner parameter
alpha = 1j
# -1 for interior Dirichlet
# +1 for exterior Dirichlet
loc_sign = +1
bdry_op_sym = (-loc_sign * 0.5 * sigma_sym + sqrt_w * (alpha * sym.S(
kernel, inv_sqrt_w_sigma, k=sym.var("k"), qbx_forced_limit=+1) - sym.D(
kernel, inv_sqrt_w_sigma, k=sym.var("k"), qbx_forced_limit="avg")))
# }}}
bound_op = bind(qbx, bdry_op_sym)
# {{{ fix rhs and solve
nodes = density_discr.nodes().with_queue(queue)
k_vec = np.array([2, 1])
k_vec = k * k_vec / la.norm(k_vec, 2)
def u_incoming_func(x):
return cl.clmath.exp(1j * (x[0] * k_vec[0] + x[1] * k_vec[1]))
bc = -u_incoming_func(nodes)
bvp_rhs = bind(qbx, sqrt_w * sym.var("bc"))(queue, bc=bc)
from pytential.solve import gmres
gmres_result = gmres(bound_op.scipy_op(queue,
"sigma",
dtype=np.complex128,
k=k),
bvp_rhs,
tol=1e-8,
progress=True,
stall_iterations=0,
hard_failure=True)
# }}}
# {{{ postprocess/visualize
sigma = gmres_result.solution
repr_kwargs = dict(k=sym.var("k"), qbx_forced_limit=None)
representation_sym = (
alpha * sym.S(kernel, inv_sqrt_w_sigma, **repr_kwargs) -
sym.D(kernel, inv_sqrt_w_sigma, **repr_kwargs))
from sumpy.visualization import FieldPlotter
fplot = FieldPlotter(np.zeros(2), extent=5, npoints=500)
targets = cl.array.to_device(queue, fplot.points)
u_incoming = u_incoming_func(targets)
qbx_stick_out = qbx.copy(target_association_tolerance=0.05)
ones_density = density_discr.zeros(queue)
ones_density.fill(1)
indicator = bind((qbx_stick_out, PointsTarget(targets)),
sym.D(LaplaceKernel(2),
sym.var("sigma"),
qbx_forced_limit=None))(queue,
sigma=ones_density).get()
try:
fld_in_vol = bind((qbx_stick_out, PointsTarget(targets)),
representation_sym)(queue, sigma=sigma, k=k).get()
except QBXTargetAssociationFailedException as e:
fplot.write_vtk_file("failed-targets.vts",
[("failed", e.failed_target_flags.get(queue))])
raise
#fplot.show_scalar_in_mayavi(fld_in_vol.real, max_val=5)
fplot.write_vtk_file("potential-helm.vts", [
("potential", fld_in_vol),
("indicator", indicator),
("u_incoming", u_incoming.get()),
])