/
near2far.cpp
157 lines (136 loc) · 5.93 KB
/
near2far.cpp
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/* Copyright (C) 2005-2015 Massachusetts Institute of Technology
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2, or (at your option)
% any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software Foundation,
% Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* Check of Green's functions (analytical vs. numerical)
and near-to-far-field transformation. */
#include <stdio.h>
#include <stdlib.h>
#include <meep.hpp>
using namespace meep;
using namespace std;
double two(const vec &) { return 2.0; }
const int EHcomp[10] = {0,1,0,1,2, 3,4,3,4,5};
int check_2d_3d(ndim dim, const double xmax, double a, component c0) {
const double dpml = 1;
if (dim != D2 && dim != D3) abort("2d or 3d required");
grid_volume gv = dim == D2 ? vol2d(xmax + 2*dpml,xmax + 2*dpml,a) : vol3d(xmax + 2*dpml,xmax + 2*dpml,xmax + 2*dpml,a);
gv.center_origin();
if (!gv.has_field(c0)) return 1;
master_printf("TESTING %s AT RESOLUTION %g FOR %s SOURCE...\n",
dim == D2 ? "2D" : "3D", a, component_name(c0));
structure s(gv, two, pml(dpml));
fields f(&s);
double w = 0.30;
continuous_src_time src(w);
f.add_point_source(c0, src, zero_vec(dim));
f.solve_cw(1e-6);
FOR_E_AND_H(c) if (gv.has_field(c)) {
const int N = 20;
double dx = 0.75 * (xmax/4) / N;
complex<double> F[N], F0[N], EH[6];
double diff = 0.0, dot0 = 0.0, dot = 0.0;
complex<double> phase = polar(1.0, (4*w*f.dt)*pi);
vec x0 = zero_vec(dim);
for (int i = 0; i < N; ++i) {
double s = xmax/4 + dx*i;
vec x = dim == D2 ? vec(s, 0.5*s) : vec(s, 0.5*s, 0.3*s);
F[i] = f.get_field(c, x) * phase;
(dim == D2 ? green2d : green3d)(EH, x, w, 2.0, 1.0, x0, c0, 1.0);
F0[i] = EH[EHcomp[c]];
double d = abs(F0[i] - F[i]);
double f = abs(F[i]);
double f0 = abs(F0[i]);
diff += d*d;
dot += f*f;
dot0 += f0*f0;
}
if (dot0 == 0) continue; /* zero field component */
double relerr = sqrt(diff) / sqrt(dot0);
master_printf(" GREEN: %s -> %s, resolution %g: relerr = %g\n",
component_name(c0), component_name(c), a, relerr);
if (relerr > 0.05 * 30/a) {
for (int i = 0; i < N; ++i)
master_printf("%g, %g,%g, %g,%g\n",
xmax/4 + dx*i,
real(F[i]), imag(F[i]),
real(F0[i]), imag(F0[i]));
return 0;
}
}
const double L = xmax/4;
volume_list vl =
dim == D2 ?
volume_list( volume(vec(-L,+L),vec(+L,+L)), Sy, 1.0,
new volume_list(volume(vec(+L,+L),vec(+L,-L)), Sx, 1.0,
new volume_list(volume(vec(-L,-L),vec(+L,-L)), Sy, -1.0,
new volume_list(volume(vec(-L,-L),vec(-L,+L)), Sx, -1.0)))) :
volume_list( volume(vec(+L,-L,-L),vec(+L,+L,+L)), Sx, +1.,
new volume_list(volume(vec(-L,-L,-L),vec(-L,+L,+L)), Sx, -1.,
new volume_list(volume(vec(-L,+L,-L),vec(+L,+L,+L)), Sy, +1.,
new volume_list(volume(vec(-L,-L,-L),vec(+L,-L,+L)), Sy, -1.,
new volume_list(volume(vec(-L,-L,+L),vec(+L,+L,+L)), Sz, +1.,
new volume_list(volume(vec(-L,-L,-L),vec(+L,+L,-L)), Sz, -1.
))))));
dft_near2far n2f = f.add_dft_near2far(&vl, w, w, 1);
f.update_dfts();
n2f.scale_dfts(sqrt(2*pi)/f.dt); // cancel time-integration factor
FOR_E_AND_H(c) if (gv.has_field(c)) {
const int N = 20;
double dx = 0.75 * (xmax/4) / N;
complex<double> F[N], F0[N], EH_[6], EH[6];
double diff = 0.0, dot = 0.0;
complex<double> phase = polar(1.0, (4*w*f.dt)*pi);
vec x0 = zero_vec(dim);
for (int i = 0; i < N; ++i) {
double s = xmax + dx*i;
vec x = dim == D2 ? vec(s, 0.5*s) : vec(s, 0.5*s, 0.3*s);
n2f.farfield_lowlevel(EH_, x);
sum_to_all(EH_, EH, 6);
F[i] = EH[EHcomp[c]] * phase;
(dim == D2 ? green2d : green3d)(EH, x, w, 2.0, 1.0, x0, c0, 1.0);
F0[i] = EH[EHcomp[c]];
double d = abs(F0[i] - F[i]);
double f0 = abs(F0[i]);
diff += d*d;
dot += f0*f0;
}
if (dot == 0) continue; /* zero field component */
double relerr = sqrt(diff) / sqrt(dot);
master_printf(" NEAR2FAR: %s -> %s, resolution %g: relerr = %g\n",
component_name(c0), component_name(c), a, relerr);
if (relerr > 0.05 * 30/a) {
for (int i = 0; i < N; ++i)
master_printf("%g, %g,%g, %g,%g\n",
xmax + dx*i,
real(F[i]), imag(F[i]),
real(F0[i]), imag(F0[i]));
return 0;
}
}
return 1;
}
int main(int argc, char **argv) {
initialize mpi(argc, argv);
const double a2d = argc > 1 ? atof(argv[1]) : 20, a3d = argc > 1 ? a2d : 10;
#if 0
FOR_E_AND_H(c0) if (!check_2d_3d(D3, 4, a3d, c0)) return 1;
#else
if (!check_2d_3d(D3, 4, a3d, Ez)) return 1;
if (!check_2d_3d(D3, 4, a3d, Hz)) return 1;
#endif
FOR_E_AND_H(c0) if (!check_2d_3d(D2, 8, a2d, c0)) return 1;
return 0;
}