kopia lustrzana https://github.com/Dsplib/libdspl-2.0
1414 wiersze
42 KiB
C
1414 wiersze
42 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 <stdio.h>
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#include <string.h>
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#include <float.h>
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#include "dspl.h"
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#include "dspl_internal.h"
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#ifdef DOXYGEN_ENGLISH
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/*! ****************************************************************************
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\ingroup DFT_GROUP
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\fn int ifft_cmplx(complex_t* x, int n, fft_t* pfft, complex_t* y)
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\brief Inverse fast Fourier transform
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Function calculates \f$ n \f$-point IFFT of complex data
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\f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
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\f[
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Y(k) = \frac{1}{N} \sum_{m = 0}^{n-1} x(m) \exp
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\left( j \frac{2\pi}{n} m k \right),
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\f]
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here \f$ k = 0 \ldots n-1 \f$.
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\param[in] x
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Pointer to the input vector \f$x(m)\f$,
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\f$ m = 0 \ldots n-1 \f$. \n
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Vector size is `[n x 1]`. \n \n
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\param[in] n
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IFFT size \f$n\f$. \n
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IFFT size can be composite:
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\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
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here \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
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simple number less than 46340
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(see \ref fft_create function). \n \n
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\param[in] pfft
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Pointer to the `fft_t` object. \n
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This pointer cannot be `NULL`. \n
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Structure \ref fft_t should be previously once
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filled with the \ref fft_create function, and the memory should be
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cleared before exiting by the \ref fft_free function. \n \n
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\param[out] y
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Pointer to the IFFT result vector \f$Y(k)\f$,
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\f$ k = 0 \ldots n-1 \f$. \n
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Vector size is `[n x 1]`. \n
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Memory must be allocated. \n \n
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\return
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`RES_OK` if IFFT is calculated successfully. \n
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Else \ref ERROR_CODE_GROUP "code error".
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IFFT example:
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\include ifft_cmplx_test.c
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Result:
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\verbatim
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| x[ 0] = 1.000 0.000 | y[ 0] = -0.517 0.686 | z[ 0] = 1.000 0.000 |
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| x[ 1] = 0.540 0.841 | y[ 1] = -0.943 0.879 | z[ 1] = 0.540 0.841 |
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| x[ 2] = -0.416 0.909 | y[ 2] = -2.299 1.492 | z[ 2] = -0.416 0.909 |
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| x[ 3] = -0.990 0.141 | y[ 3] = 16.078 -6.820 | z[ 3] = -0.990 0.141 |
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| x[ 4] = -0.654 -0.757 | y[ 4] = 2.040 -0.470 | z[ 4] = -0.654 -0.757 |
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| x[ 5] = 0.284 -0.959 | y[ 5] = 1.130 -0.059 | z[ 5] = 0.284 -0.959 |
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| x[ 6] = 0.960 -0.279 | y[ 6] = 0.786 0.097 | z[ 6] = 0.960 -0.279 |
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| x[ 7] = 0.754 0.657 | y[ 7] = 0.596 0.183 | z[ 7] = 0.754 0.657 |
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| x[ 8] = -0.146 0.989 | y[ 8] = 0.470 0.240 | z[ 8] = -0.146 0.989 |
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| x[ 9] = -0.911 0.412 | y[ 9] = 0.375 0.283 | z[ 9] = -0.911 0.412 |
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| x[10] = -0.839 -0.544 | y[10] = 0.297 0.318 | z[10] = -0.839 -0.544 |
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| x[11] = 0.004 -1.000 | y[11] = 0.227 0.350 | z[11] = 0.004 -1.000 |
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| x[12] = 0.844 -0.537 | y[12] = 0.161 0.380 | z[12] = 0.844 -0.537 |
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| x[13] = 0.907 0.420 | y[13] = 0.094 0.410 | z[13] = 0.907 0.420 |
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| x[14] = 0.137 0.991 | y[14] = 0.023 0.442 | z[14] = 0.137 0.991 |
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| x[15] = -0.760 0.650 | y[15] = -0.059 0.479 | z[15] = -0.760 0.650 |
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| x[16] = -0.958 -0.288 | y[16] = -0.161 0.525 | z[16] = -0.958 -0.288 |
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| x[17] = -0.275 -0.961 | y[17] = -0.300 0.588 | z[17] = -0.275 -0.961 |
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\endverbatim
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\author Sergey Bakhurin www.dsplib.org
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***************************************************************************** */
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#endif
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#ifdef DOXYGEN_RUSSIAN
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/*! ****************************************************************************
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\ingroup DFT_GROUP
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\fn int ifft_cmplx(complex_t* x, int n, fft_t* pfft, complex_t* y)
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\brief Обратное быстрое преобразование Фурье
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Функция рассчитывает \f$ n \f$-точечное обратное быстрое преобразование Фурье
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от \f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
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\f[
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Y(k) = \frac{1}{N} \sum_{m = 0}^{n-1} x(m) \exp
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\left( j \frac{2\pi}{n} m k \right),
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\f]
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где \f$ k = 0 \ldots n-1 \f$.
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Для расчета используется алгоритм БПФ составной длины.
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\param[in] x
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Указатель на входной комплексный вектор \f$x(m)\f$,
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\f$ m = 0 \ldots n-1 \f$. \n
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Размер вектора `[n x 1]`. \n \n
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\param[in] n
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Размер ОБПФ \f$n\f$. \n
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Размер ОБПФ может быть составным вида
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\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
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где \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
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произвольный простой множитель не превосходящий 46340
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(см. описание функции \ref fft_create). \n \n
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\param[in] pfft
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Указатель на структуру `fft_t`. \n
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Указатель не должен быть `NULL`. \n
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Структура \ref fft_t должна быть предварительно однократно
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заполнена функцией \ref fft_create, и память должна быть
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очищена перед выходом функцией \ref fft_free. \n \n
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\param[out] y
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Указатель на вектор результата ОБПФ \f$Y(k)\f$,
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\f$ k = 0 \ldots n-1 \f$. Размер вектора `[n x 1]`. \n
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Память должна быть выделена. \n \n
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\return
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`RES_OK` если расчет произведен успешно. \n
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В противном случае \ref ERROR_CODE_GROUP "код ошибки". \n \n
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Пример использования функции `fft`:
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\include ifft_cmplx_test.c
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Результат работы программы:
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\verbatim
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| x[ 0] = 1.000 0.000 | y[ 0] = -0.517 0.686 | z[ 0] = 1.000 0.000 |
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| x[ 1] = 0.540 0.841 | y[ 1] = -0.943 0.879 | z[ 1] = 0.540 0.841 |
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| x[ 2] = -0.416 0.909 | y[ 2] = -2.299 1.492 | z[ 2] = -0.416 0.909 |
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| x[ 3] = -0.990 0.141 | y[ 3] = 16.078 -6.820 | z[ 3] = -0.990 0.141 |
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| x[ 4] = -0.654 -0.757 | y[ 4] = 2.040 -0.470 | z[ 4] = -0.654 -0.757 |
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| x[ 5] = 0.284 -0.959 | y[ 5] = 1.130 -0.059 | z[ 5] = 0.284 -0.959 |
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| x[ 6] = 0.960 -0.279 | y[ 6] = 0.786 0.097 | z[ 6] = 0.960 -0.279 |
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| x[ 7] = 0.754 0.657 | y[ 7] = 0.596 0.183 | z[ 7] = 0.754 0.657 |
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| x[ 8] = -0.146 0.989 | y[ 8] = 0.470 0.240 | z[ 8] = -0.146 0.989 |
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| x[ 9] = -0.911 0.412 | y[ 9] = 0.375 0.283 | z[ 9] = -0.911 0.412 |
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| x[10] = -0.839 -0.544 | y[10] = 0.297 0.318 | z[10] = -0.839 -0.544 |
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| x[11] = 0.004 -1.000 | y[11] = 0.227 0.350 | z[11] = 0.004 -1.000 |
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| x[12] = 0.844 -0.537 | y[12] = 0.161 0.380 | z[12] = 0.844 -0.537 |
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| x[13] = 0.907 0.420 | y[13] = 0.094 0.410 | z[13] = 0.907 0.420 |
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| x[14] = 0.137 0.991 | y[14] = 0.023 0.442 | z[14] = 0.137 0.991 |
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| x[15] = -0.760 0.650 | y[15] = -0.059 0.479 | z[15] = -0.760 0.650 |
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| x[16] = -0.958 -0.288 | y[16] = -0.161 0.525 | z[16] = -0.958 -0.288 |
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| x[17] = -0.275 -0.961 | y[17] = -0.300 0.588 | z[17] = -0.275 -0.961 |
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\endverbatim
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\author Бахурин Сергей www.dsplib.org
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***************************************************************************** */
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#endif
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int DSPL_API ifft_cmplx(complex_t *x, int n, fft_t* pfft, complex_t* y)
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{
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int err, k;
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double norm;
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if(!x || !pfft || !y)
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return ERROR_PTR;
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if(n<1)
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return ERROR_SIZE;
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err = fft_create(pfft, n);
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if(err != RES_OK)
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return err;
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memcpy(pfft->t1, x, n*sizeof(complex_t));
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for(k = 0; k < n; k++)
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IM(pfft->t1[k]) = -IM(pfft->t1[k]);
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err = fft_krn(pfft->t1, pfft->t0, pfft, n, 0);
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if(err!=RES_OK)
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return err;
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norm = 1.0 / (double)n;
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for(k = 0; k < n; k++)
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{
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RE(y[k]) = RE(pfft->t0[k])*norm;
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IM(y[k]) = -IM(pfft->t0[k])*norm;
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}
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return RES_OK;
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}
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#ifdef DOXYGEN_ENGLISH
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/*! ****************************************************************************
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\ingroup DFT_GROUP
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\fn int fft(double* x, int n, fft_t* pfft, complex_t* y)
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\brief Fast Fourier transform for the real vector.
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Function calculated \f$ n \f$-points FFT for the real vector
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\f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
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\f[
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Y(k) = \sum_{m = 0}^{n-1} x(m) \exp
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\left( -j \frac{2\pi}{n} m k \right),
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\f]
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here \f$ k = 0 \ldots n-1 \f$.
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\param[in] x
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Pointer to the input real vector \f$x(m)\f$,
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\f$ m = 0 \ldots n-1 \f$. \n
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Vector size is `[n x 1]`. \n \n
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\param[in] n
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FFT size \f$n\f$. \n
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FFT size can be composite:
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\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
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here \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
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simple number less than 46340
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(see \ref fft_create function). \n \n
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\param[in] pfft
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Pointer to the `fft_t` object. \n
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This pointer cannot be `NULL`. \n
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Structure \ref fft_t should be previously once
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filled with the \ref fft_create function, and the memory should be
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cleared before exiting by the \ref fft_free function. \n \n
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\param[out] y
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Pointer to the FFT result complex vector \f$Y(k)\f$,
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\f$ k = 0 \ldots n-1 \f$. \n
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Vector size is `[n x 1]`. \n
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Memory must be allocated. \n \n
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\return
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`RES_OK` if FFT is calculated successfully. \n
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Else \ref ERROR_CODE_GROUP "code error".
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Example:
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\include fft_test.c
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Result:
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\verbatim
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y[ 0] = 91.000 0.000
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y[ 1] = -7.000 30.669
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y[ 2] = -7.000 14.536
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y[ 3] = -7.000 8.778
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y[ 4] = -7.000 5.582
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y[ 5] = -7.000 3.371
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y[ 6] = -7.000 1.598
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y[ 7] = -7.000 0.000
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y[ 8] = -7.000 -1.598
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y[ 9] = -7.000 -3.371
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y[10] = -7.000 -5.582
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y[11] = -7.000 -8.778
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y[12] = -7.000 -14.536
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y[13] = -7.000 -30.669
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\endverbatim
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\author Sergey Bakhurin www.dsplib.org
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***************************************************************************** */
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#endif
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#ifdef DOXYGEN_RUSSIAN
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/*! ****************************************************************************
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\ingroup DFT_GROUP
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\fn int fft(double* x, int n, fft_t* pfft, complex_t* y)
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\brief Быстрое преобразование Фурье вещественного сигнала
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Функция рассчитывает \f$ n \f$-точечное быстрое преобразование Фурье
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вещественного сигнала \f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
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\f[
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Y(k) = \sum_{m = 0}^{n-1} x(m) \exp
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\left( -j \frac{2\pi}{n} m k \right),
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\f]
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где \f$ k = 0 \ldots n-1 \f$.
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Для расчета используется алгоритм БПФ составной длины.
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\param[in] x
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Указатель на вектор вещественного входного сигнала \f$x(m)\f$,
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\f$ m = 0 \ldots n-1 \f$. \n
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Размер вектора `[n x 1]`. \n \n
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\param[in] n
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Размер БПФ \f$n\f$. \n
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Размер БПФ может быть составным вида
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\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
|
||
где \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
|
||
произвольный простой множитель не превосходящий 46340
|
||
(см. описание функции \ref fft_create). \n \n
|
||
|
||
\param[in] pfft
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Указатель на структуру `fft_t`. \n
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||
Указатель не должен быть `NULL`. \n
|
||
Структура \ref fft_t должна быть предварительно однократно
|
||
заполнена функцией \ref fft_create, и память должна быть
|
||
очищена перед выходом функцией \ref fft_free. \n \n
|
||
|
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\param[out] y
|
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Указатель на комплексный вектор результата БПФ \f$Y(k)\f$,
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\f$ k = 0 \ldots n-1 \f$. \n
|
||
Размер вектора `[n x 1]`. \n
|
||
Память должна быть выделена. \n \n
|
||
|
||
\return
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`RES_OK` если расчет произведен успешно. \n
|
||
В противном случае \ref ERROR_CODE_GROUP "код ошибки". \n \n
|
||
|
||
Пример использования функции `fft`:
|
||
|
||
\include fft_test.c
|
||
|
||
Результат работы программы:
|
||
|
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\verbatim
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y[ 0] = 91.000 0.000
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y[ 1] = -7.000 30.669
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y[ 2] = -7.000 14.536
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||
y[ 3] = -7.000 8.778
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||
y[ 4] = -7.000 5.582
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||
y[ 5] = -7.000 3.371
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||
y[ 6] = -7.000 1.598
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y[ 7] = -7.000 0.000
|
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y[ 8] = -7.000 -1.598
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y[ 9] = -7.000 -3.371
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y[10] = -7.000 -5.582
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y[11] = -7.000 -8.778
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y[12] = -7.000 -14.536
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y[13] = -7.000 -30.669
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\endverbatim
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\author Бахурин Сергей www.dsplib.org
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***************************************************************************** */
|
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#endif
|
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int DSPL_API fft(double* x, int n, fft_t* pfft, complex_t* y)
|
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{
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int err;
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|
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if(!x || !pfft || !y)
|
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return ERROR_PTR;
|
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if(n<1)
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return ERROR_SIZE;
|
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|
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|
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err = fft_create(pfft, n);
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if(err != RES_OK)
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return err;
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re2cmplx(x, n, pfft->t1);
|
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|
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return fft_krn(pfft->t1, y, pfft, n, 0);
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}
|
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#ifdef DOXYGEN_ENGLISH
|
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|
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#endif
|
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#ifdef DOXYGEN_RUSSIAN
|
||
|
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#endif
|
||
int DSPL_API fft_abs(double* x, int n, fft_t* pfft,
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double fs, int flag,
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||
double* mag, double* freq)
|
||
{
|
||
int k, err = RES_OK;
|
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complex_t *X = NULL;
|
||
if(!x || !pfft)
|
||
return ERROR_PTR;
|
||
|
||
if(n<1)
|
||
return ERROR_SIZE;
|
||
|
||
if(mag)
|
||
{
|
||
X = (complex_t*)malloc(n*sizeof(complex_t));
|
||
err = fft(x, n, pfft, X);
|
||
if(err!=RES_OK)
|
||
goto error_proc;
|
||
|
||
|
||
for(k = 0; k < n; k++)
|
||
mag[k] = ABS(X[k]);
|
||
if(flag & DSPL_FLAG_FFT_SHIFT)
|
||
{
|
||
err = fft_shift(mag, n, mag);
|
||
if(err!=RES_OK)
|
||
goto error_proc;
|
||
}
|
||
}
|
||
|
||
if(freq)
|
||
{
|
||
if(flag & DSPL_FLAG_FFT_SHIFT)
|
||
if(n%2)
|
||
err = linspace(-fs*0.5 + fs*0.5/(double)n,
|
||
fs*0.5 - fs*0.5/(double)n,
|
||
n, DSPL_SYMMETRIC, freq);
|
||
else
|
||
err = linspace(-fs*0.5, fs*0.5, n, DSPL_PERIODIC, freq);
|
||
else
|
||
err = linspace(0, fs, n, DSPL_PERIODIC, freq);
|
||
}
|
||
|
||
error_proc:
|
||
if(X)
|
||
free(X);
|
||
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
|
||
#endif
|
||
int DSPL_API fft_abs_cmplx(complex_t* x, int n, fft_t* pfft,
|
||
double fs, int flag,
|
||
double* mag, double* freq)
|
||
{
|
||
int k, err = RES_OK;
|
||
complex_t *X = NULL;
|
||
|
||
if(!x || !pfft)
|
||
return ERROR_PTR;
|
||
|
||
if(n<1)
|
||
return ERROR_SIZE;
|
||
|
||
if(mag)
|
||
{
|
||
X = (complex_t*)malloc(n*sizeof(complex_t));
|
||
err = fft_cmplx(x, n, pfft, X);
|
||
if(err!=RES_OK)
|
||
goto error_proc;
|
||
|
||
|
||
for(k = 0; k < n; k++)
|
||
mag[k] = ABS(X[k]);
|
||
|
||
if(flag & DSPL_FLAG_FFT_SHIFT)
|
||
{
|
||
err = fft_shift(mag, n, mag);
|
||
if(err!=RES_OK)
|
||
goto error_proc;
|
||
}
|
||
}
|
||
|
||
if(freq)
|
||
{
|
||
if(flag & DSPL_FLAG_FFT_SHIFT)
|
||
if(n%2)
|
||
err = linspace(-fs*0.5 + fs*0.5/(double)n,
|
||
fs*0.5 - fs*0.5/(double)n,
|
||
n, DSPL_SYMMETRIC, freq);
|
||
else
|
||
err = linspace(-fs*0.5, fs*0.5, n, DSPL_PERIODIC, freq);
|
||
else
|
||
err = linspace(0, fs, n, DSPL_PERIODIC, freq);
|
||
}
|
||
error_proc:
|
||
if(X)
|
||
free(X);
|
||
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_cmplx(complex_t* x, int n, fft_t* pfft, complex_t* y)
|
||
\brief Fast Fourier transform for the complex vector.
|
||
|
||
Function calculated \f$ n \f$-points FFT for the complex vector
|
||
\f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
|
||
\f[
|
||
Y(k) = \sum_{m = 0}^{n-1} x(m) \exp \left( -j \frac{2\pi}{n} m k \right),
|
||
\f]
|
||
here \f$ k = 0 \ldots n-1 \f$.
|
||
|
||
\param[in] x
|
||
Pointer to the input complex vector \f$x(m)\f$,
|
||
\f$ m = 0 \ldots n-1 \f$. \n
|
||
Vector size is `[n x 1]`. \n \n
|
||
|
||
\param[in] n
|
||
FFT size \f$n\f$. \n
|
||
FFT size can be composite:
|
||
\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
|
||
here \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
|
||
simple number less than 46340
|
||
(see \ref fft_create function). \n \n
|
||
|
||
\param[in] pfft
|
||
Pointer to the `fft_t` object. \n
|
||
This pointer cannot be `NULL`. \n
|
||
Structure \ref fft_t should be previously once
|
||
filled with the \ref fft_create function, and the memory should be
|
||
cleared before exiting by the \ref fft_free function. \n \n
|
||
|
||
\param[out] y
|
||
Pointer to the FFT result complex vector \f$Y(k)\f$,
|
||
\f$ k = 0 \ldots n-1 \f$. \n
|
||
Vector size is `[n x 1]`. \n
|
||
Memory must be allocated. \n \n
|
||
|
||
\return
|
||
`RES_OK` if FFT is calculated successfully. \n
|
||
Else \ref ERROR_CODE_GROUP "code error".
|
||
|
||
Example:
|
||
|
||
\include fft_cmplx_test.c
|
||
|
||
Result:
|
||
|
||
\verbatim
|
||
y[ 0] = -0.517 0.686
|
||
y[ 1] = -0.943 0.879
|
||
y[ 2] = -2.299 1.492
|
||
y[ 3] = 16.078 -6.820
|
||
y[ 4] = 2.040 -0.470
|
||
y[ 5] = 1.130 -0.059
|
||
y[ 6] = 0.786 0.097
|
||
y[ 7] = 0.596 0.183
|
||
y[ 8] = 0.470 0.240
|
||
y[ 9] = 0.375 0.283
|
||
y[10] = 0.297 0.318
|
||
y[11] = 0.227 0.350
|
||
y[12] = 0.161 0.380
|
||
y[13] = 0.094 0.410
|
||
y[14] = 0.023 0.442
|
||
y[15] = -0.059 0.479
|
||
y[16] = -0.161 0.525
|
||
y[17] = -0.300 0.588
|
||
\endverbatim
|
||
|
||
\author Sergey Bakhurin www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_cmplx(complex_t* x, int n, fft_t* pfft, complex_t* y)
|
||
\brief Быстрое преобразование Фурье комплексного сигнала
|
||
|
||
Функция рассчитывает \f$ n \f$-точечное быстрое преобразование Фурье
|
||
комплексного сигнала \f$ x(m) \f$, \f$ m = 0 \ldots n-1 \f$. \n
|
||
\f[
|
||
Y(k) = \sum_{m = 0}^{n-1} x(m) \exp \left( -j \frac{2\pi}{n} m k \right),
|
||
\f]
|
||
где \f$ k = 0 \ldots n-1 \f$.
|
||
|
||
Для расчета используется алгоритм БПФ составной длины.
|
||
|
||
\param[in] x
|
||
Указатель на вектор комплексного
|
||
входного сигнала \f$x(m)\f$, \f$ m = 0 \ldots n-1 \f$. \n
|
||
Размер вектора `[n x 1]`. \n \n
|
||
|
||
\param[in] n
|
||
Размер БПФ \f$n\f$. \n
|
||
Размер БПФ может быть составным вида
|
||
\f$ n = n_0 \times n_1 \times n_2 \times n_3 \times \ldots
|
||
\times n_p \times m \f$,
|
||
где \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
|
||
произвольный простой множитель не превосходящий 46340
|
||
(см. описание функции \ref fft_create). \n \n
|
||
|
||
\param[in] pfft
|
||
Указатель на структуру `fft_t`. \n
|
||
Указатель не должен быть `NULL`. \n
|
||
Структура \ref fft_t должна быть предварительно однократно
|
||
заполнена функцией \ref fft_create, и память должна быть
|
||
очищена перед выходом функцией \ref fft_free. \n \n
|
||
|
||
\param[out] y
|
||
Указатель на комплексный вектор
|
||
результата БПФ \f$Y(k)\f$,
|
||
\f$ k = 0 \ldots n-1 \f$.
|
||
Размер вектора `[n x 1]`. \n
|
||
Память должна быть выделена. \n \n
|
||
|
||
\return
|
||
`RES_OK` если расчет произведен успешно. \n
|
||
В противном случае \ref ERROR_CODE_GROUP "код ошибки". \n \n
|
||
|
||
Пример использования функции `fft`:
|
||
|
||
\include fft_cmplx_test.c
|
||
|
||
Результат работы программы:
|
||
|
||
\verbatim
|
||
y[ 0] = -0.517 0.686
|
||
y[ 1] = -0.943 0.879
|
||
y[ 2] = -2.299 1.492
|
||
y[ 3] = 16.078 -6.820
|
||
y[ 4] = 2.040 -0.470
|
||
y[ 5] = 1.130 -0.059
|
||
y[ 6] = 0.786 0.097
|
||
y[ 7] = 0.596 0.183
|
||
y[ 8] = 0.470 0.240
|
||
y[ 9] = 0.375 0.283
|
||
y[10] = 0.297 0.318
|
||
y[11] = 0.227 0.350
|
||
y[12] = 0.161 0.380
|
||
y[13] = 0.094 0.410
|
||
y[14] = 0.023 0.442
|
||
y[15] = -0.059 0.479
|
||
y[16] = -0.161 0.525
|
||
y[17] = -0.300 0.588
|
||
\endverbatim
|
||
|
||
\author Бахурин Сергей www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
int DSPL_API fft_cmplx(complex_t* x, int n, fft_t* pfft, complex_t* y)
|
||
{
|
||
int err;
|
||
|
||
if(!x || !pfft || !y)
|
||
return ERROR_PTR;
|
||
if(n<1)
|
||
return ERROR_SIZE;
|
||
|
||
err = fft_create(pfft, n);
|
||
if(err != RES_OK)
|
||
return err;
|
||
|
||
memcpy(pfft->t1, x, n*sizeof(complex_t));
|
||
|
||
return fft_krn(pfft->t1, y, pfft, n, 0);
|
||
}
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
|
||
#endif
|
||
int fft_krn(complex_t* t0, complex_t* t1, fft_t* p, int n, int addr)
|
||
{
|
||
int n1, n2, k, m, i;
|
||
complex_t *pw = p->w+addr;
|
||
complex_t tmp;
|
||
|
||
n1 = 1;
|
||
if(n % 4096 == 0) { n1 = 4096; goto label_size; }
|
||
if(n % 2048 == 0) { n1 = 2048; goto label_size; }
|
||
if(n % 1024 == 0) { n1 = 1024; goto label_size; }
|
||
if(n % 512 == 0) { n1 = 512; goto label_size; }
|
||
if(n % 256 == 0) { n1 = 256; goto label_size; }
|
||
if(n % 128 == 0) { n1 = 128; goto label_size; }
|
||
if(n % 64 == 0) { n1 = 64; goto label_size; }
|
||
if(n % 32 == 0) { n1 = 32; goto label_size; }
|
||
if(n % 16 == 0) { n1 = 16; goto label_size; }
|
||
if(n % 7 == 0) { n1 = 7; goto label_size; }
|
||
if(n % 8 == 0) { n1 = 8; goto label_size; }
|
||
if(n % 5 == 0) { n1 = 5; goto label_size; }
|
||
if(n % 4 == 0) { n1 = 4; goto label_size; }
|
||
if(n % 3 == 0) { n1 = 3; goto label_size; }
|
||
if(n % 2 == 0) { n1 = 2; goto label_size; }
|
||
|
||
label_size:
|
||
if(n1 == 1)
|
||
{
|
||
for(k = 0; k < n; k++)
|
||
{
|
||
RE(t1[k]) = IM(t1[k]) = 0.0;
|
||
for(m = 0; m < n; m++)
|
||
{
|
||
i = (k*m) % n;
|
||
RE(tmp) = CMRE(t0[m], pw[i]);
|
||
IM(tmp) = CMIM(t0[m], pw[i]);
|
||
RE(t1[k]) += RE(tmp);
|
||
IM(t1[k]) += IM(tmp);
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
n2 = n / n1;
|
||
|
||
if(n2>1)
|
||
{
|
||
memcpy(t1, t0, n*sizeof(complex_t));
|
||
matrix_transpose_cmplx(t1, n2, n1, t0);
|
||
}
|
||
|
||
if(n1 == 4096)
|
||
for(k = 0; k < n2; k++)
|
||
dft4096(t0+4096*k, t1+4096*k, p->w4096, p->w256);
|
||
|
||
if(n1 == 2048)
|
||
for(k = 0; k < n2; k++)
|
||
dft2048(t0+2048*k, t1+2048*k, p->w2048, p->w32, p->w64);
|
||
|
||
if(n1 == 1024)
|
||
for(k = 0; k < n2; k++)
|
||
dft1024(t0+1024*k, t1+1024*k, p->w1024, p->w32);
|
||
|
||
if(n1 == 512)
|
||
for(k = 0; k < n2; k++)
|
||
dft512(t0+512*k, t1+512*k, p->w512, p->w32);
|
||
|
||
if(n1 == 256)
|
||
for(k = 0; k < n2; k++)
|
||
dft256(t0+256*k, t1+256*k, p->w256);
|
||
|
||
if(n1 == 128)
|
||
for(k = 0; k < n2; k++)
|
||
dft128(t0+128*k, t1+128*k, p->w128);
|
||
|
||
if(n1 == 64)
|
||
for(k = 0; k < n2; k++)
|
||
dft64(t0+64*k, t1+64*k, p->w64);
|
||
|
||
if(n1 == 32)
|
||
for(k = 0; k < n2; k++)
|
||
dft32(t0+32*k, t1+32*k, p->w32);
|
||
|
||
if(n1 == 16)
|
||
for(k = 0; k < n2; k++)
|
||
dft16(t0+16*k, t1+16*k);
|
||
|
||
if(n1 == 7)
|
||
for(k = 0; k < n2; k++)
|
||
dft7(t0+7*k, t1+7*k);
|
||
|
||
if(n1 == 8)
|
||
for(k = 0; k < n2; k++)
|
||
dft8(t0+8*k, t1+8*k);
|
||
|
||
if(n1 == 5)
|
||
for(k = 0; k < n2; k++)
|
||
dft5(t0+5*k, t1+5*k);
|
||
|
||
if(n1 == 4)
|
||
for(k = 0; k < n2; k++)
|
||
dft4(t0+4*k, t1+4*k);
|
||
|
||
if(n1 == 3)
|
||
for(k = 0; k < n2; k++)
|
||
dft3(t0+3*k, t1+3*k);
|
||
|
||
if(n1 == 2)
|
||
for(k = 0; k < n2; k++)
|
||
dft2(t0+2*k, t1+2*k);
|
||
|
||
if(n2 > 1)
|
||
{
|
||
|
||
for(k =0; k < n; k++)
|
||
{
|
||
RE(t0[k]) = CMRE(t1[k], pw[k]);
|
||
IM(t0[k]) = CMIM(t1[k], pw[k]);
|
||
}
|
||
|
||
matrix_transpose_cmplx(t0, n1, n2, t1);
|
||
|
||
for(k = 0; k < n1; k++)
|
||
{
|
||
fft_krn(t1+k*n2, t0+k*n2, p, n2, addr+n);
|
||
}
|
||
|
||
matrix_transpose_cmplx(t0, n2, n1, t1);
|
||
}
|
||
}
|
||
return RES_OK;
|
||
}
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_create(fft_t* pfft, int n)
|
||
\brief Function creates and fill `fft_t` structure.
|
||
|
||
The function allocates memory and calculates twiddle factors
|
||
of the `n`-point FFT for the structure` fft_t`.
|
||
|
||
\param[in,out] pfft
|
||
Pointer to the `fft_t` object. \n
|
||
Pointer cannot be `NULL`. \n \n
|
||
|
||
\param[in] n
|
||
FFT size \f$n\f$. \n
|
||
FFT size can be composite
|
||
\f$n = n_0 \times n_1 \times n_2 \ldots \times n_p \times m\f$,
|
||
here \f$n_i = 2,3,5,7\f$, and \f$m \f$ --
|
||
arbitrary prime factor not exceeding 46340. \n
|
||
Thus, the FFT algorithm supports arbitrary integer lengths.
|
||
degrees of numbers 2,3,5,7, as well as their various combinations. \n
|
||
For example, with \f$ n = 725760 \f$ the structure will be successfully filled,
|
||
because
|
||
\f$ 725760 = 2 \cdot 3 \cdot 4 \cdot 5 \cdot 6 \cdot 7 \cdot 9 \cdot 16 \f$. \n
|
||
If \f$ n = 172804 = 43201 \cdot 4 \f$ then the structure will also be
|
||
successfully filled, because the simple factor in \f$ n \f$ does not
|
||
exceed 46340. \n
|
||
For size \f$ n = 13 \cdot 17 \cdot 23 \cdot 13 = 66079 \f$
|
||
the function will return an error since 66079 is greater than 46340 and is
|
||
not the result of the product of numbers 2,3,5,7. \n \n
|
||
|
||
\return
|
||
`RES_OK` if FFT structure is created and filled successfully. \n
|
||
Else \ref ERROR_CODE_GROUP "code error".
|
||
|
||
\note
|
||
Some compilers do not nullify its contents when creating a structure.
|
||
Therefore, it is recommended to reset the structure after its declaration:
|
||
\code{.cpp}
|
||
fft_t pfft = {0}; // fill and fields of fft_t as zeros
|
||
int n = 64; // FFT size
|
||
|
||
int err;
|
||
|
||
// Create fft_t object for 64-points FFT
|
||
|
||
err = fft_create(&pfft, n);
|
||
|
||
// ...................................
|
||
|
||
// Clear fft_t structure
|
||
|
||
fft_free(&pfft);
|
||
\endcode
|
||
|
||
Before exiting the program, the memory allocated in the structure
|
||
need to clear by \ref fft_free function. \n \n
|
||
|
||
\note
|
||
The "magic number" 46340 because \f$\sqrt{2^{31}} = 46340.95\f$. \n
|
||
|
||
\author Sergey Bakhurin www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_create(fft_t* pfft, int n)
|
||
\brief Заполнение структуры `fft_t` для алгоритма БПФ
|
||
|
||
Функция производит выделение памяти и рассчет векторов
|
||
поворотных коэффициентов `n`-точечного БПФ для структуры `fft_t`.
|
||
|
||
\param[in,out] pfft
|
||
Указатель на структуру `fft_t`. \n
|
||
Указатель не должен быть `NULL`. \n \n
|
||
|
||
\param[in] n
|
||
Размер БПФ \f$n\f$. \n
|
||
Размер БПФ может быть составным вида
|
||
\f$n = n_0 \times n_1 \times n_2 \ldots \times n_p \times m\f$,
|
||
где \f$n_i = 2,3,5,7\f$, а \f$m \f$ --
|
||
произвольный простой множитель не превосходящий 46340. \n
|
||
Таким образом алгоритм БПФ поддерживает произвольные длины, равные целой
|
||
степени чисел 2,3,5,7, а также различные их комбинации. \n
|
||
Так например, при \f$ n = 725760 \f$ структура будет успешно заполнена,
|
||
потому что
|
||
\f$725760 = 2 \cdot 3 \cdot 4 \cdot 5 \cdot 6 \cdot 7 \cdot 9 \cdot 16 \f$,
|
||
т.е. получается как произведение множителей 2,3,5,7. \n
|
||
При \f$ n = 172804 = 43201 \cdot 4 \f$ структура также будет успешно заполнена,
|
||
потому что простой множитель входящий в \f$n\f$ не превосходит 46340. \n
|
||
Для размера \f$ n = 13 \cdot 17 \cdot 23 \cdot 13 = 66079 \f$
|
||
функция вернет ошибку, поскольку 66079 больше 46340 и не является результатом
|
||
произведения чисел 2,3,5,7. \n \n
|
||
|
||
\return
|
||
`RES_OK` если структура заполнена успешно. \n
|
||
В противном случае \ref ERROR_CODE_GROUP "код ошибки". \n \n
|
||
|
||
\note
|
||
Некоторые компиляторы при создании структуры не обнуляют ее содержимое.
|
||
Поэтому рекомендуется произвести обнуление структуры после ее объявления:
|
||
\code{.cpp}
|
||
fft_t pfft = {0}; // объявляем объект fft_t
|
||
int n = 64; // Размер БПФ
|
||
|
||
int err;
|
||
|
||
// создаем объект для 64-точечного БПФ
|
||
|
||
err = fft_create(&pfft, n);
|
||
|
||
// ...................................
|
||
|
||
// очистить память объекта БПФ
|
||
|
||
fft_free(&pfft);
|
||
\endcode
|
||
|
||
Перед выходом из программы выделенную в структуре память
|
||
необходимо очистить функцией \ref fft_free . \n \n
|
||
|
||
\note
|
||
Магия числа 46340 заключается в том, что \f$\sqrt{2^{31}} = 46340.95\f$. \n
|
||
|
||
\author Бахурин Сергей www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
int DSPL_API fft_create(fft_t* pfft, int n)
|
||
{
|
||
|
||
int n1, n2, addr, s, k, m, nw, err;
|
||
double phi;
|
||
s = n;
|
||
nw = addr = 0;
|
||
|
||
if(pfft->n == n)
|
||
return RES_OK;
|
||
|
||
while(s > 1)
|
||
{
|
||
n2 = 1;
|
||
if(s%4096 == 0) { n2 = 4096; goto label_size; }
|
||
if(s%2048 == 0) { n2 = 2048; goto label_size; }
|
||
if(s%1024 == 0) { n2 = 1024; goto label_size; }
|
||
if(s%512 == 0) { n2 = 512; goto label_size; }
|
||
if(s%256 == 0) { n2 = 256; goto label_size; }
|
||
if(s%128 == 0) { n2 = 128; goto label_size; }
|
||
if(s% 64 == 0) { n2 = 64; goto label_size; }
|
||
if(s% 32 == 0) { n2 = 32; goto label_size; }
|
||
if(s% 16 == 0) { n2 = 16; goto label_size; }
|
||
if(s% 7 == 0) { n2 = 7; goto label_size; }
|
||
if(s% 8 == 0) { n2 = 8; goto label_size; }
|
||
if(s% 5 == 0) { n2 = 5; goto label_size; }
|
||
if(s% 4 == 0) { n2 = 4; goto label_size; }
|
||
if(s% 3 == 0) { n2 = 3; goto label_size; }
|
||
if(s% 2 == 0) { n2 = 2; goto label_size; }
|
||
|
||
|
||
label_size:
|
||
if(n2 == 1)
|
||
{
|
||
if(s > FFT_COMPOSITE_MAX)
|
||
{
|
||
err = ERROR_FFT_SIZE;
|
||
goto error_proc;
|
||
}
|
||
|
||
nw += s;
|
||
pfft->w = pfft->w ?
|
||
(complex_t*) realloc(pfft->w, nw*sizeof(complex_t)):
|
||
(complex_t*) malloc( nw*sizeof(complex_t));
|
||
for(k = 0; k < s; k++)
|
||
{
|
||
phi = - M_2PI * (double)k / (double)s;
|
||
RE(pfft->w[addr]) = cos(phi);
|
||
IM(pfft->w[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
s = 1;
|
||
}
|
||
else
|
||
{
|
||
n1 = s / n2;
|
||
nw += s;
|
||
pfft->w = pfft->w ?
|
||
(complex_t*) realloc(pfft->w, nw*sizeof(complex_t)):
|
||
(complex_t*) malloc( nw*sizeof(complex_t));
|
||
|
||
for(k = 0; k < n1; k++)
|
||
{
|
||
for(m = 0; m < n2; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / (double)s;
|
||
RE(pfft->w[addr]) = cos(phi);
|
||
IM(pfft->w[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
}
|
||
s /= n2;
|
||
}
|
||
|
||
pfft->t0 = pfft->t0 ? (complex_t*) realloc(pfft->t0, n*sizeof(complex_t)):
|
||
(complex_t*) malloc( n*sizeof(complex_t));
|
||
|
||
pfft->t1 = pfft->t1 ? (complex_t*) realloc(pfft->t1, n*sizeof(complex_t)):
|
||
(complex_t*) malloc( n*sizeof(complex_t));
|
||
pfft->n = n;
|
||
|
||
/* w32 fill */
|
||
addr = 0;
|
||
for(k = 0; k < 4; k++)
|
||
{
|
||
for(m = 0; m < 8; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 32.0;
|
||
RE(pfft->w32[addr]) = cos(phi);
|
||
IM(pfft->w32[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
|
||
|
||
/* w64 fill */
|
||
addr = 0;
|
||
for(k = 0; k < 8; k++)
|
||
{
|
||
for(m = 0; m < 8; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 64.0;
|
||
RE(pfft->w64[addr]) = cos(phi);
|
||
IM(pfft->w64[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
|
||
/* w128 fill */
|
||
addr = 0;
|
||
for(k = 0; k < 8; k++)
|
||
{
|
||
for(m = 0; m < 16; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 128.0;
|
||
RE(pfft->w128[addr]) = cos(phi);
|
||
IM(pfft->w128[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
|
||
/* w256 fill */
|
||
addr = 0;
|
||
for(k = 0; k < 16; k++)
|
||
{
|
||
for(m = 0; m < 16; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 256.0;
|
||
RE(pfft->w256[addr]) = cos(phi);
|
||
IM(pfft->w256[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
|
||
/* w512 fill */
|
||
addr = 0;
|
||
for(k = 0; k < 16; k++)
|
||
{
|
||
for(m = 0; m < 32; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 512.0;
|
||
RE(pfft->w512[addr]) = cos(phi);
|
||
IM(pfft->w512[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
|
||
/* w1024 fill */
|
||
if(pfft->w1024 == NULL)
|
||
{
|
||
pfft->w1024 = (complex_t*) malloc(1024 * sizeof(complex_t));
|
||
addr = 0;
|
||
for(k = 0; k < 32; k++)
|
||
{
|
||
for(m = 0; m < 32; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 1024.0;
|
||
RE(pfft->w1024[addr]) = cos(phi);
|
||
IM(pfft->w1024[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* w2048 fill */
|
||
if(pfft->w2048 == NULL)
|
||
{
|
||
pfft->w2048= (complex_t*) malloc(2048 * sizeof(complex_t));
|
||
addr = 0;
|
||
for(k = 0; k < 32; k++)
|
||
{
|
||
for(m = 0; m < 64; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 2048.0;
|
||
RE(pfft->w2048[addr]) = cos(phi);
|
||
IM(pfft->w2048[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* w4096 fill */
|
||
if(pfft->w4096 == NULL)
|
||
{
|
||
pfft->w4096= (complex_t*) malloc(4096 * sizeof(complex_t));
|
||
addr = 0;
|
||
for(k = 0; k < 16; k++)
|
||
{
|
||
for(m = 0; m < 256; m++)
|
||
{
|
||
phi = - M_2PI * (double)(k*m) / 4096.0;
|
||
RE(pfft->w4096[addr]) = cos(phi);
|
||
IM(pfft->w4096[addr]) = sin(phi);
|
||
addr++;
|
||
}
|
||
}
|
||
}
|
||
|
||
return RES_OK;
|
||
error_proc:
|
||
if(pfft->t0) free(pfft->t0);
|
||
if(pfft->t1) free(pfft->t1);
|
||
if(pfft->w) free(pfft->w);
|
||
pfft->n = 0;
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn void fft_free(fft_t *pfft)
|
||
\brief Free `fft_t` structure.
|
||
|
||
The function clears the intermediate data memory
|
||
and vectors of FFT twiddle factors of the structure `fft_t`.
|
||
|
||
\param[in] pfft
|
||
Pointer to the `fft_t` object. \n
|
||
|
||
\author Sergey Bakhurin www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn void fft_free(fft_t *pfft)
|
||
\brief Очистить структуру `fft_t` алгоритма БПФ
|
||
|
||
Функция производит очищение памяти промежуточных данных
|
||
и векторов поворотных коэффициентов структуры `fft_t`.
|
||
|
||
\param[in] pfft
|
||
Указатель на структуру `fft_t`. \n
|
||
|
||
\author Бахурин Сергей www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
void DSPL_API fft_free(fft_t *pfft)
|
||
{
|
||
if(!pfft)
|
||
return;
|
||
if(pfft->w)
|
||
free(pfft->w);
|
||
if(pfft->t0)
|
||
free(pfft->t0);
|
||
if(pfft->t1)
|
||
free(pfft->t1);
|
||
|
||
if(pfft->w1024)
|
||
free(pfft->w1024);
|
||
|
||
if(pfft->w2048)
|
||
free(pfft->w2048);
|
||
|
||
if(pfft->w4096)
|
||
free(pfft->w4096);
|
||
|
||
memset(pfft, 0, sizeof(fft_t));
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
|
||
#endif
|
||
int DSPL_API fft_mag(double* x, int n, fft_t* pfft,
|
||
double fs, int flag,
|
||
double* mag, double* freq)
|
||
{
|
||
int k, err;
|
||
err = fft_abs(x, n, pfft, fs, flag, mag, freq);
|
||
if(err != RES_OK)
|
||
return err;
|
||
if(mag)
|
||
{
|
||
if(flag & DSPL_FLAG_LOGMAG)
|
||
for(k = 0; k < n; k++)
|
||
mag[k] = 20.0 * log10(mag[k] + DBL_EPSILON);
|
||
else
|
||
for(k = 0; k < n; k++)
|
||
mag[k] *= mag[k];
|
||
}
|
||
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
|
||
#endif
|
||
int DSPL_API fft_mag_cmplx(complex_t* x, int n, fft_t* pfft,
|
||
double fs, int flag,
|
||
double* mag, double* freq)
|
||
{
|
||
int k, err;
|
||
err = fft_abs_cmplx(x, n, pfft, fs, flag, mag, freq);
|
||
if(err != RES_OK)
|
||
return err;
|
||
if(mag)
|
||
{
|
||
if(flag & DSPL_FLAG_LOGMAG)
|
||
for(k = 0; k < n; k++)
|
||
mag[k] = 20.0 * log10(mag[k] + DBL_EPSILON);
|
||
else
|
||
for(k = 0; k < n; k++)
|
||
mag[k] *= mag[k];
|
||
}
|
||
|
||
return err;
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_shift(double* x, int n, double* y)
|
||
\brief Perform a shift of the vector `x`, for use with the `fft` and `ifft`
|
||
functions, in order
|
||
<a href="http://en.dsplib.org/content/dft_freq/dft_freq.html">
|
||
to move the frequency 0 to the center
|
||
</a> of the vector `y`.
|
||
|
||
\param[in] x
|
||
Pointer to the input vector (FFT or IFFT result). \n
|
||
Vector size is `[n x 1]`. \n \n
|
||
|
||
\param[in] n
|
||
Input and output vector size. \n \n
|
||
|
||
\param[out] y
|
||
Pointer to the output vector with frequency 0 in the center. \n
|
||
Vector size is `[n x 1]`. \n
|
||
Memory must be allocated. \n \n
|
||
|
||
|
||
\return
|
||
`RES_OK` if function is calculated successfully. \n
|
||
Else \ref ERROR_CODE_GROUP "code error".
|
||
|
||
\author Sergey Bakhurin www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
/*! ****************************************************************************
|
||
\ingroup DFT_GROUP
|
||
\fn int fft_shift(double* x, int n, double* y)
|
||
\brief Перестановка спектральных отсчетов дискретного преобразования Фурье
|
||
|
||
Функция производит
|
||
<a href="http://ru.dsplib.org/content/dft_freq/dft_freq.html">
|
||
перестановку спектральных отсчетов ДПФ
|
||
</a> и переносит нулевую частоту в центр вектора ДПФ. \n
|
||
Данная функция обрабатывает вещественные входные и выходные вектора
|
||
и может применяться для перестановки
|
||
амплитудного или фазового спектра.
|
||
|
||
\param[in] x
|
||
Указатель на исходный вектор ДПФ. \n
|
||
Размер вектора `[n x 1]`. \n \n
|
||
|
||
\param[in] n
|
||
Размер ДПФ \f$n\f$ (размер векторов до и после перестановки). \n \n
|
||
|
||
\param[out] y
|
||
Указатель на вектор результата перестановки. \n
|
||
Размер вектора `[n x 1]`. \n
|
||
Память должна быть выделена. \n \n
|
||
|
||
\return
|
||
`RES_OK` если перестановка произведена успешно. \n
|
||
В противном случае \ref ERROR_CODE_GROUP "код ошибки". \n
|
||
|
||
\author Бахурин Сергей www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
int DSPL_API fft_shift(double* x, int n, double* y)
|
||
{
|
||
int n2, r;
|
||
int k;
|
||
double tmp;
|
||
double *buf;
|
||
|
||
if(!x || !y)
|
||
return ERROR_PTR;
|
||
|
||
if(n<1)
|
||
return ERROR_SIZE;
|
||
|
||
r = n%2;
|
||
if(!r)
|
||
{
|
||
n2 = n>>1;
|
||
for(k = 0; k < n2; k++)
|
||
{
|
||
tmp = x[k];
|
||
y[k] = x[k+n2];
|
||
y[k+n2] = tmp;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
n2 = (n+1) >> 1;
|
||
buf = (double*) malloc(n2*sizeof(double));
|
||
memcpy(buf, x, n2*sizeof(double));
|
||
memcpy(y, x+n2, (n2-1)*sizeof(double));
|
||
memcpy(y+n2-1, buf, n2*sizeof(double));
|
||
free(buf);
|
||
}
|
||
return RES_OK;
|
||
}
|
||
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
|
||
#endif
|
||
int DSPL_API fft_shift_cmplx(complex_t* x, int n, complex_t* y)
|
||
{
|
||
int n2, r;
|
||
int k;
|
||
complex_t tmp;
|
||
complex_t *buf;
|
||
|
||
if(!x || !y)
|
||
return ERROR_PTR;
|
||
|
||
if(n<1)
|
||
return ERROR_SIZE;
|
||
|
||
r = n%2;
|
||
if(!r)
|
||
{
|
||
n2 = n>>1;
|
||
for(k = 0; k < n2; k++)
|
||
{
|
||
RE(tmp) = RE(x[k]);
|
||
IM(tmp) = IM(x[k]);
|
||
|
||
RE(y[k]) = RE(x[k+n2]);
|
||
IM(y[k]) = IM(x[k+n2]);
|
||
|
||
RE(y[k+n2]) = RE(tmp);
|
||
IM(y[k+n2]) = IM(tmp);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
n2 = (n+1) >> 1;
|
||
buf = (complex_t*) malloc(n2*sizeof(complex_t));
|
||
memcpy(buf, x, n2*sizeof(complex_t));
|
||
memcpy(y, x+n2, (n2-1)*sizeof(complex_t));
|
||
memcpy(y+n2-1, buf, n2*sizeof(complex_t));
|
||
free(buf);
|
||
}
|
||
return RES_OK;
|
||
}
|
||
|