![]() |
NFFT
3.3.0
|
Data Structures | |
struct | fgt_plan |
Structure for the Gauss transform. More... | |
Macros | |
#define | NFFT_PRECISION_DOUBLE |
#define | DGT_PRE_CEXP (1U<< 0) |
If this flag is set, the whole matrix is precomputed and stored for the discrete Gauss transfrom. More... | |
#define | FGT_NDFT (1U<< 1) |
If this flag is set, the fast Gauss transform uses the discrete instead of the fast Fourier transform. More... | |
#define | FGT_APPROX_B (1U<< 2) |
If this flag is set, the discrete Fourier coefficients of the uniformly sampled Gaussian are used instead of the sampled continuous Fourier transform. More... | |
Functions | |
static void | dgt_trafo (fgt_plan *ths) |
Executes the discrete Gauss transform. More... | |
static void | fgt_trafo (fgt_plan *ths) |
Executes the fast Gauss transform. More... | |
static void | fgt_init_guru (fgt_plan *ths, int N, int M, NFFT_C sigma, int n, NFFT_R p, int m, unsigned flags) |
Initialisation of a transform plan, guru. More... | |
static void | fgt_init (fgt_plan *ths, int N, int M, NFFT_C sigma, NFFT_R eps) |
Initialisation of a transform plan, simple. More... | |
static void | fgt_init_node_dependent (fgt_plan *ths) |
Initialisation of a transform plan, depends on source and target nodes. More... | |
static void | fgt_finalize (fgt_plan *ths) |
Destroys the transform plan. More... | |
static void | fgt_test_init_rand (fgt_plan *ths) |
Random initialisation of a fgt plan. More... | |
static NFFT_R | fgt_test_measure_time (fgt_plan *ths, unsigned dgt) |
Compares execution times for the fast and discrete Gauss transform. More... | |
static void | fgt_test_simple (int N, int M, NFFT_C sigma, NFFT_R eps) |
Simple example that computes fast and discrete Gauss transforms. More... | |
static void | fgt_test_andersson (void) |
Compares accuracy and execution time of the fast Gauss transform with increasing expansion degree. More... | |
static void | fgt_test_error (void) |
Compares accuracy of the fast Gauss transform with increasing expansion degree. More... | |
static void | fgt_test_error_p (void) |
Compares accuracy of the fast Gauss transform with increasing expansion degree and different periodisation lengths. More... | |
int | main (int argc, char **argv) |
Different tests of the fast Gauss transform. More... | |
#define DGT_PRE_CEXP (1U<< 0) |
If this flag is set, the whole matrix is precomputed and stored for the discrete Gauss transfrom.
Definition at line 44 of file fastgauss.c.
Referenced by dgt_trafo(), fgt_init(), fgt_init_node_dependent(), and fgt_test_andersson().
#define FGT_NDFT (1U<< 1) |
If this flag is set, the fast Gauss transform uses the discrete instead of the fast Fourier transform.
Definition at line 55 of file fastgauss.c.
Referenced by fgt_test_andersson(), and fgt_trafo().
#define FGT_APPROX_B (1U<< 2) |
If this flag is set, the discrete Fourier coefficients of the uniformly sampled Gaussian are used instead of the sampled continuous Fourier transform.
Definition at line 65 of file fastgauss.c.
Referenced by fgt_init_guru().
|
static |
Executes the discrete Gauss transform.
Definition at line 103 of file fastgauss.c.
References fgt_plan::alpha, DGT_PRE_CEXP, fgt_plan::f, fgt_plan::flags, fgt_plan::M, fgt_plan::N, fgt_plan::pre_cexp, fgt_plan::sigma, fgt_plan::x, and fgt_plan::y.
Referenced by fgt_test_error(), fgt_test_error_p(), fgt_test_measure_time(), and fgt_test_simple().
|
static |
Executes the fast Gauss transform.
Definition at line 130 of file fastgauss.c.
References fgt_plan::b, FGT_NDFT, fgt_plan::flags, and fgt_plan::n.
Referenced by fgt_test_error(), fgt_test_error_p(), fgt_test_measure_time(), and fgt_test_simple().
|
static |
Initialisation of a transform plan, guru.
Definition at line 168 of file fastgauss.c.
References fgt_plan::alpha, fgt_plan::b, fgt_plan::f, FGT_APPROX_B, fgt_plan::flags, fgt_plan::M, fgt_plan::N, fgt_plan::n, fgt_plan::p, fgt_plan::sigma, fgt_plan::x, and fgt_plan::y.
Referenced by fgt_init(), fgt_test_andersson(), fgt_test_error(), and fgt_test_error_p().
|
static |
Initialisation of a transform plan, simple.
Definition at line 242 of file fastgauss.c.
References DGT_PRE_CEXP, and fgt_init_guru().
Referenced by fgt_test_simple().
|
static |
Initialisation of a transform plan, depends on source and target nodes.
Definition at line 263 of file fastgauss.c.
References DGT_PRE_CEXP, fgt_plan::flags, fgt_plan::M, fgt_plan::N, fgt_plan::p, fgt_plan::pre_cexp, fgt_plan::sigma, fgt_plan::x, and fgt_plan::y.
Referenced by fgt_test_andersson(), fgt_test_error(), fgt_test_error_p(), and fgt_test_simple().
|
static |
Destroys the transform plan.
Definition at line 294 of file fastgauss.c.
References fgt_plan::alpha, fgt_plan::b, fgt_plan::f, fgt_plan::x, and fgt_plan::y.
Referenced by fgt_test_andersson(), fgt_test_error(), fgt_test_error_p(), and fgt_test_simple().
|
static |
Random initialisation of a fgt plan.
Definition at line 317 of file fastgauss.c.
References fgt_plan::alpha, fgt_plan::M, fgt_plan::N, fgt_plan::x, and fgt_plan::y.
Referenced by fgt_test_andersson(), fgt_test_error(), fgt_test_error_p(), and fgt_test_simple().
|
static |
Compares execution times for the fast and discrete Gauss transform.
Definition at line 340 of file fastgauss.c.
References dgt_trafo(), and fgt_trafo().
Referenced by fgt_test_andersson().
|
static |
Simple example that computes fast and discrete Gauss transforms.
Definition at line 375 of file fastgauss.c.
References fgt_plan::alpha, dgt_trafo(), fgt_plan::f, fgt_finalize(), fgt_init(), fgt_init_node_dependent(), fgt_test_init_rand(), fgt_trafo(), fgt_plan::M, and fgt_plan::N.
Referenced by main().
|
static |
Compares accuracy and execution time of the fast Gauss transform with increasing expansion degree.
Similar to the test in F. Andersson and G. Beylkin. The fast Gauss transform with complex parameters. J. Comput. Physics 203 (2005) 274-286
Definition at line 411 of file fastgauss.c.
References fgt_plan::alpha, DGT_PRE_CEXP, fgt_plan::f, fgt_finalize(), fgt_init_guru(), fgt_init_node_dependent(), FGT_NDFT, fgt_test_init_rand(), fgt_test_measure_time(), fgt_plan::flags, fgt_plan::M, and fgt_plan::N.
Referenced by main().
|
static |
Compares accuracy of the fast Gauss transform with increasing expansion degree.
Definition at line 477 of file fastgauss.c.
References fgt_plan::alpha, dgt_trafo(), fgt_plan::f, fgt_finalize(), fgt_init_guru(), fgt_init_node_dependent(), fgt_test_init_rand(), fgt_trafo(), fgt_plan::M, and fgt_plan::N.
Referenced by main().
|
static |
Compares accuracy of the fast Gauss transform with increasing expansion degree and different periodisation lengths.
Definition at line 529 of file fastgauss.c.
References fgt_plan::alpha, dgt_trafo(), fgt_plan::f, fgt_finalize(), fgt_init_guru(), fgt_init_node_dependent(), fgt_test_init_rand(), fgt_trafo(), fgt_plan::M, and fgt_plan::N.
Referenced by main().
int main | ( | int | argc, |
char ** | argv | ||
) |
Different tests of the fast Gauss transform.
Definition at line 578 of file fastgauss.c.
References fgt_test_andersson(), fgt_test_error(), fgt_test_error_p(), and fgt_test_simple().