Ok, I've found something baffling!
Replace
(set! geometry-lattice (make lattice (size *no-size no-size no-size*)))
(set-param! resolution 20)
with something like
(set! geometry-lattice (make lattice (size *1 1 1*)))
(set-param! resolution 20)
The output gives you too many frequencies! I even increased the resolution
but still cant get the same result
This is exactly what happens in my CPP code!
Any idea how to get same result with finite size object? when no-size is
used what is the resolution? if it is still 20 why when I change the
dimension to 1, this problem occurs?
Thanks
Joe
On Mon, Jun 7, 2010 at 4:23 PM, joe ertaba belav...@gmail.com wrote:
Hi,
I've tried to convert a simple example of
http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Material_dispersioninto
a C++ code.
Attached is my simple code. I was wondering, although I use same variables
as the example why I get wrong variables
For K=[0.3, 0, 0] ctl file gives:
freqs:, 1, 0.3, 0, 0, 0.180392569033513, 1.22101799986358
While C++ gives:
Too many frequencies!
P.S: The only difference I can assume is that I use Ez component for
Harminv peak detection, maybe in ctl something else is used!
I really appreciate if somebody can check my file
Thanks
Joe
/*MY CODE
(CPP)***/
#include meep.hpp
using namespace meep;
typedef complexdouble dcomp;
//Structure
const double xWidth = 1.0;
const double yWidth = 1.0;
const double zWidth = 1.0;
const double resolution = 20; // pixels per distance
//Source
const double freq = 1.0;
const double dfreq = 0.9; //fractional
const component srcComp = Ez;
const vec srcPosition = vec (0.5, 0.5, 0.5);
//Sampling
const component sampleComp = Ez;
const int maxNumOfBands = 10;
//Run Time
const double timeAfterSource = 200.0;
//functions
double eps(const vec p) {
return 2.25;
}
double sigma1(const vec p) {
return 0.5;
}
double sigma2(const vec p) {
return 2e-5;
}
int main(int argc, char **argv) {
initialize mpi(argc, argv);
/** Structure */
grid_volume v = vol3d(xWidth, yWidth, zWidth, resolution);
structure s(v, eps);
/**Output*/
const char *dirname = make_output_directory(~/Desktop/run);
s.set_output_directory(dirname);
s.add_polarizability (sigma1, E_stuff, 1.1, 1e-5); //(sigma, field_type
E_stuff, omega_n, gamma_n);
s.add_polarizability (sigma2, E_stuff, 0.5, 0.1);
fields f(s);
//Harminv variables
int NumOfSamples = int(timeAfterSource / f.dt + 0.5) + 1;
dcomp *samplePoint = new dcomp[NumOfSamples];
/** Source*/
double freq_min = freq * (1 - dfreq);
double freq_max = freq * (1 + dfreq);
gaussian_src_time src((freq_min + freq_max) * 0.5, 0.5 / fabs(freq_max
- freq_min), 0, 5 / fabs(freq_max - freq_min));
f.add_point_source(srcComp, src, srcPosition);
//
vec kVector = vec(0.3, 0.0, 0.0);
f.use_bloch(kVector);
/** Run*/
while (f.time() f.last_source_time()) {
f.step();
}
int i = 0;
while (f.time() f.last_source_time() + timeAfterSource) {
samplePoint[i] = f.get_field(sampleComp, srcPosition);
i++;
f.step();
}
/** Harmonic Inversion*/
dcomp amp[maxNumOfBands];
double freq_re[maxNumOfBands], freq_im[maxNumOfBands],
freq_err[maxNumOfBands];
int num1_freqs = do_harminv(samplePoint, i, f.dt, freq_min / 4.0,
freq_max * 4.0, maxNumOfBands,
amp, freq_re, freq_im, freq_err);
/** Results*/
for (int i = 0; i num1_freqs; ++i) {
master_printf(freq[%d] = %g%+gi +/- %g (amp %g%+gi) Q = %g\n,i,
freq_re[i], freq_im[i], freq_err[i], real(amp[i]), imag(amp[i]), -0.5 *
freq_re[i] / freq_im[i]);
}
delete[] samplePoint;
return 0;
}
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