src/fourier.c File Reference

#include <it/types.h>
#include <it/fourier.h>
#include <it/io.h>
#include <it/math.h>

Go to the source code of this file.

Defines
#define	CACHE_SIZE   128*1024
#define	DFT_LAST   16
#define	FDFT_FORW   0
#define	FDFT_BACK   1
Functions
static int	intlog2 (int n)
void	fft_init (void)
static void	cplx_array_bitrev_permute (cplx *v, int n)
static void	__fft_dif (cplx *v, int log2n)
static void	__ifft_dit (cplx *v, int log2n)
static void	_fft (cplx *v, int log2n)
static void	_ifft (cplx *v, int log2n)
static void	_fft_demangle (cplx *v, int log2n)
static void	_ifft_mangle (cplx *v, int log2n)
cvec	it_fft (cvec v)
cvec	it_ifft (cvec v)
cvec	cvec_fft_conv (cvec a, cvec b)
cvec	cvec_fft_corr (cvec a, cvec b)
cvec	cvec_fft_autocorr (cvec a)
cvec	it_fzt (cvec v, cplx z)
static cvec	it_fdft (cvec v, int inv)
static cvec	it_sdft (cvec v)
static cvec	it_sidft (cvec v)
cvec	it_dft (cvec v)
cvec	it_idft (cvec v)
cvec	it_dft_real (vec v)
vec	it_idft_real (cvec cv)
Variables
static unsigned int	cache_size = CACHE_SIZE
static int	fft_init_done = 0
static int	fft_log2size
static cvec	dft_roots [DFT_LAST]
static cvec	fft_roots
static ivec	fft_perm

---

Define Documentation

#define CACHE_SIZE   128*1024

Definition at line 48 of file fourier.c.

#define DFT_LAST   16

Definition at line 49 of file fourier.c.

Referenced by fft_init(), it_dft(), it_idft(), it_sdft(), and it_sidft().

#define FDFT_BACK   1

Definition at line 643 of file fourier.c.

Referenced by it_idft().

#define FDFT_FORW   0

Definition at line 642 of file fourier.c.

Referenced by it_dft().

---

Function Documentation

static void __fft_dif	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 137 of file fourier.c.

References cadd(), cmul(), csub(), and fft_log2size.

Referenced by _fft().

static void __ifft_dit	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 168 of file fourier.c.

References cadd(), cmul(), csub(), and fft_log2size.

Referenced by _ifft().

static void _fft	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 208 of file fourier.c.

References __fft_dif(), cmul(), cvec_delete(), cvec_new(), fft_log2size, fft_perm, _cplx_::i, M_PI, and _cplx_::r.

Referenced by cvec_fft_autocorr(), cvec_fft_conv(), cvec_fft_corr(), it_fdft(), it_fft(), and it_fzt().

static void _fft_demangle	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 347 of file fourier.c.

References cplx_array_bitrev_permute(), and fft_log2size.

Referenced by it_fft().

static void _ifft	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 274 of file fourier.c.

References __ifft_dit(), cmul(), cvec_delete(), cvec_new(), fft_log2size, fft_perm, _cplx_::i, M_PI, and _cplx_::r.

Referenced by cvec_fft_autocorr(), cvec_fft_conv(), cvec_fft_corr(), it_fdft(), it_fzt(), and it_ifft().

static void _ifft_mangle	(	cplx *	v,
		int	log2n
	)			[static]

Definition at line 383 of file fourier.c.

References cplx_array_bitrev_permute(), and fft_log2size.

Referenced by it_ifft().

static void cplx_array_bitrev_permute	(	cplx *	v,
		int	n
	)			[inline, static]

Definition at line 108 of file fourier.c.

References cplx_swap.

Referenced by _fft_demangle(), and _ifft_mangle().

void fft_init

(

void

)

Definition at line 71 of file fourier.c.

References cache_size, cplx_1, cvec_new_unit_roots(), cvec_push, DFT_LAST, fft_init_done, fft_log2size, fft_perm, intlog2(), and ivec_new().

Referenced by cvec_fft_autocorr(), cvec_fft_conv(), cvec_fft_corr(), it_fdft(), it_fft(), it_fzt(), it_ifft(), it_sdft(), and it_sidft().

static int intlog2

(

int

n

)

[inline, static]

Definition at line 61 of file fourier.c.

Referenced by cvec_fft_autocorr(), cvec_fft_conv(), cvec_fft_corr(), fft_init(), it_dft(), it_fdft(), it_fft(), it_fzt(), it_idft(), and it_ifft().

static cvec it_fdft	(	cvec	v,
		int	inv
	)			[static]

Definition at line 644 of file fourier.c.

References _fft(), _ifft(), cimag, cmul(), cplx_0, cplx_1, creal, cscale(), cvec_delete(), cvec_length(), cvec_mul(), cvec_new(), cvec_new_zeros(), cvec_set_length, fft_init(), _cplx_::i, intlog2(), M_PI, and _cplx_::r.

Referenced by it_dft(), and it_idft().

static cvec it_sdft

(

cvec

v

)

[static]

Definition at line 719 of file fourier.c.

References cadd(), cmul(), cplx_0, cvec_length(), cvec_new(), DFT_LAST, fft_init(), and N.

Referenced by it_dft().

static cvec it_sidft

(

cvec

v

)

[static]

Definition at line 745 of file fourier.c.

References cadd(), cmul(), cplx_0, cvec_div_by_real(), cvec_length(), cvec_new(), DFT_LAST, fft_init(), and N.

Referenced by it_idft().

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Variable Documentation

unsigned int cache_size = CACHE_SIZE [static]

Definition at line 51 of file fourier.c.

Referenced by fft_init().

cvec dft_roots[DFT_LAST] [static]

Definition at line 56 of file fourier.c.

int fft_init_done = 0 [static]

Definition at line 54 of file fourier.c.

Referenced by fft_init().

int fft_log2size [static]

Definition at line 55 of file fourier.c.

Referenced by __fft_dif(), __ifft_dit(), _fft(), _fft_demangle(), _ifft(), _ifft_mangle(), and fft_init().

ivec fft_perm [static]

Definition at line 58 of file fourier.c.

Referenced by _fft(), _ifft(), and fft_init().

cvec fft_roots [static]

Definition at line 57 of file fourier.c.