kopia lustrzana https://github.com/Dsplib/libdspl-2.0
110 wiersze
2.6 KiB
C
110 wiersze
2.6 KiB
C
/*
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* Copyright (c) 2015-2019 Sergey Bakhurin
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* Digital Signal Processing Library [http://dsplib.org]
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*
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* This file is part of libdspl-2.0.
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*
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* is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* DSPL is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include "dspl.h"
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/******************************************************************************
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Goertzel algorithm for real vector
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*******************************************************************************/
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int DSPL_API goertzel(double *x, int n, int *ind, int k, complex_t *y)
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{
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int m, p;
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double wR, wI;
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double alpha;
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double v[3];
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if(!x || !y || !ind)
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return ERROR_PTR;
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if(n < 1 || k < 1)
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return ERROR_SIZE;
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for(p = 0; p < k; p++)
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{
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wR = cos(M_2PI * (double)ind[p] / (double)n);
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wI = sin(M_2PI * (double)ind[p] / (double)n);
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alpha = 2.0 * wR;
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v[0] = v[1] = v[2] = 0.0;
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for(m = 0; m < n; m++)
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{
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v[2] = v[1];
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v[1] = v[0];
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v[0] = x[m]+alpha*v[1] - v[2];
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}
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RE(y[p]) = wR * v[0] - v[1];
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IM(y[p]) = wI * v[0];
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}
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return RES_OK;
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}
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/******************************************************************************
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Goertzel algorithm for complex vector
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*******************************************************************************/
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int DSPL_API goertzel_cmplx(complex_t *x, int n, int *ind, int k, complex_t *y)
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{
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int m, p;
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complex_t w;
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double alpha;
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complex_t v[3];
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if(!x || !y || !ind)
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return ERROR_PTR;
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if(n < 1 || k < 1)
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return ERROR_SIZE;
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for(p = 0; p < k; p++)
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{
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RE(w) = cos(M_2PI * (double)ind[p] / (double)n);
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IM(w) = sin(M_2PI * (double)ind[p] / (double)n);
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alpha = 2.0 * RE(w);
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memset(v, 0, 3*sizeof(complex_t));
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for(m = 0; m < n; m++)
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{
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RE(v[2]) = RE(v[1]);
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RE(v[1]) = RE(v[0]);
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RE(v[0]) = RE(x[m]) + alpha * RE(v[1]) - RE(v[2]);
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IM(v[2]) = IM(v[1]);
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IM(v[1]) = IM(v[0]);
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IM(v[0]) = IM(x[m]) + alpha * IM(v[1]) - IM(v[2]);
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}
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RE(y[p]) = CMRE(w, v[0]) - RE(v[1]);
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IM(y[p]) = CMIM(w, v[0]) - IM(v[1]);
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}
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return RES_OK;
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}
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