| NFFT 3.5.0

- Main Page
- Modules
- Data Structures
- Files

- File List
- Globals

Macros | Functions
fpt.c File Reference

Implementation file for the FPT module. More...

`#include "config.h"`
`#include <stdlib.h>`
`#include <string.h>`
`#include <stdbool.h>`
`#include <math.h>`
`#include "nfft3.h"`
`#include "infft.h"`
`#include "fpt.h"`
Include dependency graph for fpt.c:

Go to the source code of this file.

## Macros
#define | K_START_TILDE(x, y) (MAX(MIN(x,y-2),0))
| If defined, perform critical computations in three-term recurrence always in long double instead of using adaptive version that starts in double and switches to long double if required. More...
#define | K_END_TILDE(x, y) MIN(x,y-1)
| Maximum degree at top of a cascade.
#define | FIRST_L(x, y) (LRINT(floor((x)/(double)y)))
| Index of first block of four functions at level.
#define | LAST_L(x, y) (LRINT(ceil(((x)+1)/(double)y))-1)
| Index of last block of four functions at level.
#define | N_TILDE(y) (y-1)
#define | IS_SYMMETRIC(x, y, z) (x >= ((y-1.0)/z))
#define | FPT_BREAK_EVEN 4
#define | ABUVXPWY_SYMMETRIC(NAME, S1, S2)
#define | ABUVXPWY_SYMMETRIC_1(NAME, S1)
#define | ABUVXPWY_SYMMETRIC_2(NAME, S1)
#define | FPT_DO_STEP(NAME, M1_FUNCTION, M2_FUNCTION)
#define | FPT_DO_STEP_TRANSPOSED(NAME, M1_FUNCTION, M2_FUNCTION)

## Functions
static void | abuvxpwy (double a, double b, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n)
static void | abuvxpwy_symmetric1 (double a, double b, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n)
static void | abuvxpwy_symmetric2 (double a, double b, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n)
static void | abuvxpwy_symmetric1_1 (double a, double b, double _Complex *u, double _Complex *x, double *v, double _Complex *y, int n, double *xx)
static void | abuvxpwy_symmetric1_2 (double a, double b, double _Complex *u, double _Complex *x, double *v, double _Complex *y, int n, double *xx)
static void | abuvxpwy_symmetric2_1 (double a, double b, double _Complex *u, double _Complex *x, double _Complex *y, double *w, int n, double *xx)
static void | abuvxpwy_symmetric2_2 (double a, double b, double _Complex *u, double _Complex *x, double _Complex *y, double *w, int n, double *xx)
static void | auvxpwy (double a, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n)
static void | auvxpwy_symmetric (double a, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n)
static void | auvxpwy_symmetric_1 (double a, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n, double *xx)
static void | auvxpwy_symmetric_2 (double a, double _Complex *u, double _Complex *x, double *v, double _Complex *y, double *w, int n, double *xx)
static void | fpt_do_step (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double g, int tau, fpt_set set)
static void | fpt_do_step_symmetric (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double g, int tau, fpt_set set)
static void | fpt_do_step_symmetric_u (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double *x, double gam, int tau, fpt_set set)
static void | fpt_do_step_symmetric_l (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double *x, double gam, int tau, fpt_set set)
static void | fpt_do_step_t (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double g, int tau, fpt_set set)
static void | fpt_do_step_t_symmetric (double _Complex *a, double _Complex *b, double *a11, double *a12, double *a21, double *a22, double g, int tau, fpt_set set)
static void | fpt_do_step_t_symmetric_u (double _Complex *a, double _Complex *b, double *a11, double *a12, double *x, double gam, int tau, fpt_set set)
static void | fpt_do_step_t_symmetric_l (double _Complex *a, double _Complex *b, double *a21, double *a22, double *x, double gam, int tau, fpt_set set)
static void | eval_clenshaw (const double *x, double *y, int size, int k, const double *alpha, const double *beta, const double *gam)
static void | eval_clenshaw2 (const double *x, double *z, double *y, int size1, int size, int k, const double *alpha, const double *beta, const double *gam)
static int | eval_clenshaw_thresh2 (const double *x, double *z, double *y, int size, int k, const double *alpha, const double *beta, const double *gam, const double threshold)
static void | eval_sum_clenshaw_fast (const int N, const int M, const double _Complex *a, const double *x, double _Complex *y, const double *alpha, const double *beta, const double *gam, const double lambda)
static void | eval_sum_clenshaw_transposed (int N, int M, double _Complex *a, double *x, double _Complex *y, double _Complex *temp, double *alpha, double *beta, double *gam, double lambda)
| Clenshaw algorithm. More...
static void | eval_sum_clenshaw_transposed_ld (int N, int M, double _Complex *a, double *x, double _Complex *y, double _Complex *temp, double *alpha, double *beta, double *gam, double lambda)
fpt_set | fpt_init (const int M, const int t, const unsigned int flags)
void | fpt_precompute_1 (fpt_set set, const int m, int k_start)
void | fpt_precompute_2 (fpt_set set, const int m, double *alpha, double *beta, double *gam, int k_start, const double threshold)
void | fpt_precompute (fpt_set set, const int m, double *alpha, double *beta, double *gam, int k_start, const double threshold)
void | fpt_trafo_direct (fpt_set set, const int m, const double _Complex *x, double _Complex *y, const int k_end, const unsigned int flags)
void | fpt_trafo (fpt_set set, const int m, const double _Complex *x, double _Complex *y, const int k_end, const unsigned int flags)
void | fpt_transposed_direct (fpt_set set, const int m, double _Complex *x, double _Complex *y, const int k_end, const unsigned int flags)
void | fpt_transposed (fpt_set set, const int m, double _Complex *x, double _Complex *y, const int k_end, const unsigned int flags)
void | fpt_finalize (fpt_set set)

## Detailed Description

Implementation file for the FPT module.

Author
  Jens Keiner

Definition in file fpt.c.

## Macro Definition Documentation

#define K_START_TILDE | ( |  | x,
|  |  | y
| ) |  | (MAX(MIN(x,y-2),0))

If defined, perform critical computations in three-term recurrence always in long double instead of using adaptive version that starts in double and switches to long double if required.

Minimum degree at top of a cascade

Definition at line 48 of file fpt.c.

Referenced by fpt_init(), fpt_precompute(), and fpt_transposed().

#define ABUVXPWY_SYMMETRIC | ( |  | NAME,
|  |  | S1,
|  |  | S2
| ) |  |

Value:
static inline void NAME(double a, double b, double _Complex* u, double _Complex* x, \
double* v, double _Complex* y, double* w, int n) \
{ \
const int n2 = n>>1; \
int l; double _Complex *u_ptr = u, *x_ptr = x, *y_ptr = y; \
double *v_ptr = v, *w_ptr = w; \
for (l = 0; l < n2; l++) \
*u_ptr++ = a * (b * (*v_ptr++) * (*x_ptr++) + (*w_ptr++) * (*y_ptr++)); \
v_ptr--; w_ptr--; \
for (l = 0; l < n2; l++) \
*u_ptr++ = a * (b * S1 * (*v_ptr--) * (*x_ptr++) + S2 * (*w_ptr--) * (*y_ptr++)); \
}

Definition at line 77 of file fpt.c.

#define ABUVXPWY_SYMMETRIC_1 | ( |  | NAME,
|  |  | S1
| ) |  |

Value:
static inline void NAME(double a, double b, double _Complex* u, double _Complex* x, \
double* v, double _Complex* y, int n, double *xx) \
{ \
const int n2 = n>>1; \
int l; double _Complex *u_ptr = u, *x_ptr = x, *y_ptr = y; \
double *v_ptr = v, *xx_ptr = xx; \
for (l = 0; l < n2; l++, v_ptr++) \
*u_ptr++ = a * (b * (*v_ptr) * (*x_ptr++) + ((*v_ptr)*(1.0+*xx_ptr++)) * (*y_ptr++)); \
v_ptr--; \
for (l = 0; l < n2; l++, v_ptr--) \
*u_ptr++ = a * (b * S1 * (*v_ptr) * (*x_ptr++) + (S1 * (*v_ptr) * (1.0+*xx_ptr++)) * (*y_ptr++)); \
}

Definition at line 94 of file fpt.c.

#define ABUVXPWY_SYMMETRIC_2 | ( |  | NAME,
|  |  | S1
| ) |  |

Value:
static inline void NAME(double a, double b, double _Complex* u, double _Complex* x, \
double _Complex* y, double* w, int n, double *xx) \
{ \
const int n2 = n>>1; \
int l; double _Complex *u_ptr = u, *x_ptr = x, *y_ptr = y; \
double *w_ptr = w, *xx_ptr = xx; \
for (l = 0; l < n2; l++, w_ptr++) \
*u_ptr++ = a * (b * (*w_ptr/(1.0+*xx_ptr++)) * (*x_ptr++) + (*w_ptr) * (*y_ptr++)); \
w_ptr--; \
for (l = 0; l < n2; l++, w_ptr--) \
*u_ptr++ = a * (b * (S1 * (*w_ptr)/(1.0+*xx_ptr++) ) * (*x_ptr++) + S1 * (*w_ptr) * (*y_ptr++)); \
}

Definition at line 111 of file fpt.c.

#define FPT_DO_STEP_TRANSPOSED | ( |  | NAME,
|  |  | M1_FUNCTION,
|  |  | M2_FUNCTION
| ) |  |

Value:
static inline void NAME(double _Complex *a, double _Complex *b, double *a11, \
double *a12, double *a21, double *a22, double g, int tau, fpt_set set) \
{ \ \
int length = 1<<(tau+1); \ \
double norm = 1.0/(length<<1); \
\
/* Compute function values from Chebyshev-coefficients using a DCT-III. */ \
fftw_execute_r2r(set->plans_dct3[tau-1],(double*)a,(double*)a); \
fftw_execute_r2r(set->plans_dct3[tau-1],(double*)b,(double*)b); \
\
/* Perform matrix multiplication. */ \
M1_FUNCTION(norm,g,set->z,a,a11,b,a21,length); \
M2_FUNCTION(norm,g,b,a,a12,b,a22,length); \
memcpy(a,set->z,length*sizeof(double _Complex)); \
\
/* Compute Chebyshev-coefficients using a DCT-II. */ \
fftw_execute_r2r(set->plans_dct2[tau-1],(double*)a,(double*)a); \
fftw_execute_r2r(set->plans_dct2[tau-1],(double*)b,(double*)b); \
}
fpt_set_s_
Holds data for a set of cascade summations.
Definition: fpt.h:65

Definition at line 335 of file fpt.c.

## Function Documentation

static void eval_sum_clenshaw_transposed | ( | int | N,
|  | int | M,
|  | double _Complex * | a,
|  | double * | x,
|  | double _Complex * | y,
|  | double _Complex * | temp,
|  | double * | alpha,
|  | double * | beta,
|  | double * | gam,
|  | double | lambda
| ) |  |
| static

Clenshaw algorithm.

Evaluates a sum of real-valued functions

obeying a three-term recurrence relation

with initial conditions , for given double _Complex coefficients at given nodes , .

Definition at line 717 of file fpt.c.

Referenced by fpt_precompute().