kopia lustrzana https://github.com/Dsplib/libdspl-2.0
77 wiersze
2.2 KiB
C
77 wiersze
2.2 KiB
C
/*
|
|
* Copyright (c) 2015-2019 Sergey Bakhurin
|
|
* Digital Signal Processing Library [http://dsplib.org]
|
|
*
|
|
* This file is part of libdspl-2.0.
|
|
*
|
|
* is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Lesser General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* DSPL 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 Lesser General Public License
|
|
* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <math.h>
|
|
#include "dspl.h"
|
|
|
|
|
|
#ifdef DOXYGEN_ENGLISH
|
|
|
|
#endif
|
|
#ifdef DOXYGEN_RUSSIAN
|
|
|
|
#endif
|
|
int DSPL_API fourier_series_dec_cmplx(double* t, complex_t* s, int nt,
|
|
double period, int nw, double* w, complex_t* y)
|
|
{
|
|
int k, m;
|
|
double dw = M_2PI / period;
|
|
complex_t e[2];
|
|
|
|
if(!t || !s || !w || !y)
|
|
return ERROR_PTR;
|
|
if(nt<1 || nw < 1)
|
|
return ERROR_SIZE;
|
|
if(period <= 0.0)
|
|
return ERROR_NEGATIVE;
|
|
|
|
memset(y, 0 , nw*sizeof(complex_t));
|
|
|
|
for(k = 0; k < nw; k++)
|
|
{
|
|
w[k] = (k - nw/2) * dw;
|
|
RE(e[1]) = RE(s[0]) * cos(w[k] * t[0]) +
|
|
IM(s[0]) * sin(w[k] * t[0]);
|
|
IM(e[1]) = -RE(s[0]) * sin(w[k] * t[0]) +
|
|
IM(s[0]) * cos(w[k] * t[0]);
|
|
for(m = 1; m < nt; m++)
|
|
{
|
|
RE(e[0]) = RE(e[1]);
|
|
IM(e[0]) = IM(e[1]);
|
|
RE(e[1]) = RE(s[m]) * cos(w[k] * t[m]) +
|
|
IM(s[m]) * sin(w[k] * t[m]);
|
|
IM(e[1]) = -RE(s[m]) * sin(w[k] * t[m]) +
|
|
IM(s[m]) * cos(w[k] * t[m]);
|
|
RE(y[k]) += 0.5 * (RE(e[0]) + RE(e[1]))*(t[m] - t[m-1]);
|
|
IM(y[k]) += 0.5 * (IM(e[0]) + IM(e[1]))*(t[m] - t[m-1]);
|
|
}
|
|
RE(y[k]) /= period;
|
|
IM(y[k]) /= period;
|
|
}
|
|
|
|
if(!(nw%2))
|
|
RE(y[0]) = RE(y[1]) = 0.0;
|
|
|
|
return RES_OK;
|
|
}
|