NFFT 3.2.3 API Reference - nfft3util.h File Reference

Header file for utility functions used by the nfft3 library. More...

#include <fftw3.h>

Macros
#define	NFFT_SWAP_complex(x, y)
	Swapping of two vectors.
#define	NFFT_SWAP_double(x, y)
	Swapping of two vectors.
#define	PI 3.141592653589793238462643383279502884197169399375105820974944592
	Formerly known to be an irrational number.
#define	PI2 6.283185307179586476925286766559005768394338798750211641949889185
#define	PI4 12.56637061435917295385057353311801153678867759750042328389977837
#define	NFFT_MAX(a, b) ((a)>(b)? (a) : (b))
	Maximum of its two arguments.
#define	NFFT_MIN(a, b) ((a)<(b)? (a) : (b))
	Mimimum of its two arguments.

Functions
double	nfft_bspline_old (int k, double x, double *A)
	To test the new one.
double	nfft_bspline (int k, double x, double *scratch)
	Computes the B-spline $M_{k,0}\left(x\right)$ , scratch is used for de Boor's scheme.
int	nfft_prod_int (int *vec, int d)
	Computes integer $\prod_{t=0}^{d-1} v_t$ .
int	nfst_prod_minus_a_int (int *vec, int a, int d)
	Computes integer $\prod_{t=0}^{d-1} v_t-a$ .
int	nfft_plain_loop (int idx, int N, int d)
	Computes $\sum_{t=0}^{d-1} i_t \prod_{t'=t+1}^{d-1} N_{t'}$ .
double	nfft_prod_real (double *vec, int d)
	Computes double $\prod_{t=0}^{d-1} v_t$ .
double	nfft_dot_complex (fftw_complex *x, int n)
	Computes the inner/dot product .
double	nfft_dot_double (double *x, int n)
	Computes the inner/dot product .
double	nfft_dot_w_complex (fftw_complex x, double w, int n)
	Computes the weighted inner/dot product $x^H (w \odot x)$ .
double	nfft_dot_w_double (double x, double w, int n)
	Computes the weighted inner/dot product $x^H (w \odot x)$ .
double	nfft_dot_w_w2_complex (fftw_complex x, double w, double *w2, int n)
	Computes the weighted inner/dot product $x^H (w1\odot w2\odot w2 \odot x)$ .
double	nfft_dot_w2_complex (fftw_complex x, double w2, int n)
	Computes the weighted inner/dot product $x^H (w2\odot w2 \odot x)$ .
void	nfft_cp_complex (fftw_complex x, fftw_complex y, int n)
	Copies $x \leftarrow y$ .
void	nfft_cp_double (double x, double y, int n)
	Copies $x \leftarrow y$ .
void	nfft_cp_a_complex (fftw_complex x, double a, fftw_complex y, int n)
	Copies $x \leftarrow a y$ .
void	nfft_cp_a_double (double x, double a, double y, int n)
	Copies $x \leftarrow a y$ .
void	nfft_cp_w_complex (fftw_complex x, double w, fftw_complex *y, int n)
	Copies $x \leftarrow w\odot y$ .
void	nfft_cp_w_double (double x, double w, double *y, int n)
	Copies $x \leftarrow w\odot y$ .
void	nfft_upd_axpy_complex (fftw_complex x, double a, fftw_complex y, int n)
	Updates $x \leftarrow a x + y$ .
void	nfft_upd_axpy_double (double x, double a, double y, int n)
	Updates $x \leftarrow a x + y$ .
void	nfft_upd_xpay_complex (fftw_complex x, double a, fftw_complex y, int n)
	Updates $x \leftarrow x + a y$ .
void	nfft_upd_xpay_double (double x, double a, double y, int n)
	Updates $x \leftarrow x + a y$ .
void	nfft_upd_axpby_complex (fftw_complex x, double a, fftw_complex y, double b, int n)
	Updates $x \leftarrow a x + b y$ .
void	nfft_upd_axpby_double (double x, double a, double y, double b, int n)
	Updates $x \leftarrow a x + b y$ .
void	nfft_upd_xpawy_complex (fftw_complex x, double a, double w, fftw_complex *y, int n)
	Updates $x \leftarrow x + a w\odot y$ .
void	nfft_upd_xpawy_double (double x, double a, double w, double *y, int n)
	Updates $x \leftarrow x + a w\odot y$ .
void	nfft_upd_axpwy_complex (fftw_complex x, double a, double w, fftw_complex *y, int n)
	Updates $x \leftarrow a x + w\odot y$ .
void	nfft_upd_axpwy_double (double x, double a, double w, double *y, int n)
	Updates $x \leftarrow a x + w\odot y$ .
void	nfft_fftshift_complex (fftw_complex x, int d, int N)
	Swaps each half over N[d]/2.
void	nfft_vpr_int (int x, int n, char text)
	Prints a vector of integer numbers.
void	nfft_vpr_double (double x, int n, const char text)
	Prints a vector of doubles numbers.
void	nfft_vpr_complex (fftw_complex x, int n, const char text)
	Prints a vector of complex numbers.
void	nfft_vrand_unit_complex (fftw_complex *x, int n)
	Inits a vector of random complex numbers in $[0,1]\times[0,1]{\rm i}$ .
void	nfft_vrand_shifted_unit_double (double *x, int n)
	Inits a vector of random double numbers in .
void	nfft_voronoi_weights_1d (double w, double x, int M)
	Computes non periodic voronoi weights, assumes ordered nodes .
void	nfft_voronoi_weights_S2 (double w, double xi, int M)
	Computes voronoi weights for nodes on the sphere S^2.
double	nfft_modified_fejer (int N, int kk)
	Computes the damping factor for the modified Fejer kernel, ie $\frac{2}{N}\left(1-\frac{\left\|2k+1\right\|}{N}\right)$ .
double	nfft_modified_jackson2 (int N, int kk)
	Computes the damping factor for the modified Jackson kernel.
double	nfft_modified_jackson4 (int N, int kk)
	Computes the damping factor for the modified generalised Jackson kernel.
double	nfft_modified_sobolev (double mu, int kk)
	Computes the damping factor for the modified Sobolev kernel.
double	nfft_modified_multiquadric (double mu, double c, int kk)
	Computes the damping factor for the modified multiquadric kernel.
int	nfft_smbi (const double x, const double alpha, const int nb, const int ize, double *b)
	Calculates the modified bessel function $I_{n+\alpha}(x)$ , possibly scaled by $\mathrm{e}^{-x}$ , for real non-negative with $0 \le \alpha < 1$ , and $n=0,1,\ldots,nb-1$ .
double	nfft_drand48 (void)
void	nfft_srand48 (long int seed)
void	nfft_sort_node_indices_radix_lsdf (int n, int keys0, int keys1, int rhigh)
	Radix sort for node indices.
void	nfft_sort_node_indices_radix_msdf (int n, int keys0, int keys1, int rhigh)
	Radix sort for node indices.
int	nfft_get_num_threads (void)

Detailed Description

Header file for utility functions used by the nfft3 library.

Definition in file nfft3util.h.

Macros

Functions

Detailed Description