NFFT  3.3.2
Functions
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
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
kubintkern (const R x, const C *Add, const int Ad, const R a)
 linear spline interpolation in near field with even kernels
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 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 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
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
void fastsum_finalize (fastsum_plan *ths)
 finalization of fastsum plan
void fastsum_exact (fastsum_plan *ths)
 direct computation of sums
void fastsum_precompute (fastsum_plan *ths)
 precomputation for fastsum
void fastsum_trafo (fastsum_plan *ths)
 fast NFFT-based summation

Detailed Description

Fast NFFT-based summation algorithm.

Author:
Markus Fenn
Date:
2003-2006

Definition in file fastsum.c.