kopia lustrzana https://github.com/Dsplib/libdspl-2.0
96 wiersze
2.9 KiB
C
96 wiersze
2.9 KiB
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "dspl.h"
|
|
|
|
|
|
#define N 8192
|
|
#define FS 1.0
|
|
|
|
|
|
|
|
void psd_plot(int argc, char* argv[], char* fn_png, char* fn_data)
|
|
{
|
|
char cmd[512] = {0};
|
|
void* hplot; /* GNUPLOT handle */
|
|
/* plotting by GNUPLOT */
|
|
gnuplot_create(argc, argv, 680, 480, fn_png, &hplot);
|
|
gnuplot_cmd(hplot, "unset key");
|
|
gnuplot_cmd(hplot, "set grid");
|
|
gnuplot_cmd(hplot, "set xlabel 'frequency, Hz'");
|
|
gnuplot_cmd(hplot, "set ylabel 'Power Spectral Density, [dB/Hz]'");
|
|
gnuplot_cmd(hplot, "set yrange [-60: 40]");
|
|
|
|
sprintf(cmd, "plot '%s' w l lt -1", fn_data);
|
|
|
|
gnuplot_cmd(hplot, cmd);
|
|
gnuplot_close(hplot);
|
|
}
|
|
|
|
|
|
int main(int argc, char* argv[])
|
|
{
|
|
void* hdspl; /* DSPL handle */
|
|
|
|
hdspl = dspl_load(); /* Load DSPL function */
|
|
random_t rnd = {0}; /* random structure */
|
|
|
|
complex_t *x = NULL;
|
|
double *psd = NULL;
|
|
double *frq = NULL;
|
|
|
|
int k, err;
|
|
|
|
x = (complex_t*)malloc(N*sizeof(complex_t));
|
|
psd = (double*)malloc(N*sizeof(double));
|
|
frq = (double*)malloc(N*sizeof(double));
|
|
|
|
/* input signal fill as noise -20 dB/Hz power spectrum density */
|
|
random_init(&rnd, RAND_TYPE_MRG32K3A, NULL);
|
|
randn_cmplx(x, N, NULL, 0.1, &rnd);
|
|
|
|
/* x[k] = 0.1 * cos(2 * pi * 0.2 * k) + cos(2 * pi * 0.26 * k) + noise */
|
|
for(k = 0; k < N; k++)
|
|
{
|
|
RE(x[k]) += cos(M_2PI * 0.26 * (double)k) +
|
|
0.1*cos(M_2PI*0.2* (double)k);
|
|
|
|
IM(x[k]) += sin(M_2PI * 0.26 * (double)k) +
|
|
0.1*sin(M_2PI*0.2* (double)k);
|
|
}
|
|
/* Twosided PSD logscale magnitude n = 8192, nfft = 8192.
|
|
This case is periodogram */
|
|
err = psd_bartlett_cmplx(x, N, N, NULL, FS,
|
|
DSPL_FLAG_LOGMAG | DSPL_FLAG_PSD_TWOSIDED, psd, frq);
|
|
writetxt(frq, psd, N, "dat/psd_bartlett_cmplx_8192.txt");
|
|
psd_plot(argc, argv, "img/psd_bartlett_cmplx_8192.png",
|
|
"dat/psd_bartlett_cmplx_8192.txt");
|
|
|
|
|
|
/* Twosided PSD with logscale magnitude n = 8192, nfft = 1024 */
|
|
err = psd_bartlett_cmplx(x, N, N/8, NULL, FS,
|
|
DSPL_FLAG_LOGMAG | DSPL_FLAG_PSD_TWOSIDED, psd, frq);
|
|
writetxt(frq, psd, N/8, "dat/psd_bartlett_cmplx_1024.txt");
|
|
psd_plot(argc, argv, "img/psd_bartlett_cmplx_1024.png",
|
|
"dat/psd_bartlett_cmplx_1024.txt");
|
|
|
|
|
|
/* Twosided PSD with logscale magnitude n = 8192, nfft = 128 */
|
|
err = psd_bartlett_cmplx(x, N, N/64, NULL, FS,
|
|
DSPL_FLAG_LOGMAG | DSPL_FLAG_PSD_TWOSIDED, psd, frq);
|
|
writetxt(frq, psd, N/64, "dat/psd_bartlett_cmplx_128.txt");
|
|
psd_plot(argc, argv, "img/psd_bartlett_cmplx_128.png",
|
|
"dat/psd_bartlett_cmplx_128.txt");
|
|
|
|
dspl_free(hdspl); /* free dspl handle */
|
|
if(x)
|
|
free(x);
|
|
if(psd)
|
|
free(psd);
|
|
if(frq)
|
|
free(frq);
|
|
return 0;
|
|
}
|
|
|
|
|