fastsum.c File Reference

Fast NFFT-based summation algorithm. More...

#include "config.h"
#include <stdlib.h>
#include <math.h>
#include "nfft3.h"
#include "fastsum.h"
#include "infft.h"
#include "kernels.h"

Go to the source code of this file.

Functions
static int	max_i (int a, int b)
	max
static R	fak (int n)
	factorial
static R	binom (int n, int m)
	binomial coefficient
static R	BasisPoly (int m, int r, R xx)
	basis polynomial for regularized kernel
C	regkern (kernel k, R xx, int p, const R *param, R a, R b)
	regularized kernel with K_I arbitrary and K_B smooth to zero
static C	regkern1 (kernel k, R xx, int p, const R *param, R a, R b)
	regularized kernel with K_I arbitrary and K_B periodized (used in 1D)
static C	regkern3 (kernel k, R xx, int p, const R *param, R a, R b)
	regularized kernel for even kernels with K_I even and K_B mirrored More...
C	kubintkern (const R x, const C *Add, const int Ad, const R a)
	linear spline interpolation in near field with even kernels More...
static C	kubintkern1 (const R x, const C *Add, const int Ad, const R a)
	cubic spline interpolation in near field with arbitrary kernels
static void	quicksort (int d, int t, R *x, C *alpha, int *permutation_x_alpha, int N)
	quicksort algorithm for source knots and associated coefficients
static void	BuildBox (fastsum_plan *ths)
	initialize box-based search data structures
static C	calc_SearchBox (int d, R *y, R *x, C *alpha, int start, int end_lt, const C *Add, const int Ad, int p, R a, const kernel k, const R *param, const unsigned flags)
	inner computation function for box-based near field correction
static C	SearchBox (R *y, fastsum_plan *ths)
	box-based near field correction
static void	BuildTree (int d, int t, R *x, C *alpha, int *permutation_x_alpha, int N)
	recursive sort of source knots dimension by dimension to get tree structure
static C	SearchTree (const int d, const int t, const R *x, const C *alpha, const R *xmin, const R *xmax, const int N, const kernel k, const R *param, const int Ad, const C *Add, const int p, const unsigned flags)
	fast search in tree of source knots for near field computation
static void	fastsum_precompute_kernel (fastsum_plan *ths)
void	fastsum_init_guru_kernel (fastsum_plan *ths, int d, kernel k, R *param, unsigned flags, int nn, int p, R eps_I, R eps_B)
	initialize node independent part of fast summation plan More...
void	fastsum_init_guru_source_nodes (fastsum_plan *ths, int N_total, int nn_oversampled, int m)
	initialize source nodes dependent part of fast summation plan More...
void	fastsum_init_guru_target_nodes (fastsum_plan *ths, int M_total, int nn_oversampled, int m)
	initialize target nodes dependent part of fast summation plan More...
void	fastsum_init_guru (fastsum_plan *ths, int d, int N_total, int M_total, kernel k, R *param, unsigned flags, int nn, int m, int p, R eps_I, R eps_B)
	initialization of fastsum plan More...
void	fastsum_finalize_source_nodes (fastsum_plan *ths)
	finalization of fastsum plan More...
void	fastsum_finalize_target_nodes (fastsum_plan *ths)
	finalization of fastsum plan More...
void	fastsum_finalize_kernel (fastsum_plan *ths)
	finalization of fastsum plan More...
void	fastsum_finalize (fastsum_plan *ths)
	finalization of fastsum plan More...
void	fastsum_exact (fastsum_plan *ths)
	direct computation of sums More...
void	fastsum_precompute_source_nodes (fastsum_plan *ths)
	precomputation for fastsum More...
void	fastsum_precompute_target_nodes (fastsum_plan *ths)
	precomputation for fastsum More...
void	fastsum_precompute (fastsum_plan *ths)
	precomputation for fastsum More...
void	fastsum_trafo (fastsum_plan *ths)
	fast NFFT-based summation More...

Detailed Description

Fast NFFT-based summation algorithm.

Author

Markus Fenn

Date

2003-2006

Definition in file fastsum.c.