Direct and fast computation of the discrete nonequispaced cosine transform. More...

Data Structures
struct	nfct_plan
	data structure for an NFCT (nonequispaced fast cosine transform) plan with double precision More...

Functions
void	nfct_init_1d (nfct_plan *ths_plan, int N0, int M_total)

void	nfct_init_2d (nfct_plan *ths_plan, int N0, int N1, int M_total)

void	nfct_init_3d (nfct_plan *ths_plan, int N0, int N1, int N2, int M_total)

void	nfct_init (nfct_plan ths_plan, int d, int N, int M_total)

void	nfct_precompute_psi (nfct_plan *ths)

void	nfct_trafo (nfct_plan *ths_plan)

void	nfct_adjoint (nfct_plan *ths_plan)

void	nfct_finalize (nfct_plan *ths_plan)

Detailed Description

Direct and fast computation of the discrete nonequispaced cosine transform.

Function Documentation

Creates a 1-dimensional transform plan.

Creates a 3-dimensional transform plan.

Creates a 3-dimensional transform plan.

Creates a d-dimensional transform plan.

void nfct_precompute_psi ( nfct_plan * ths_plan )

precomputes the values psi if the PRE_PSI is set the application program has to call this routine after setting the nodes this_plan->x

void nfct_trafo ( nfct_plan * ths_plan )

executes a NFCT (approximate,fast), computes for $j=0,...,M\_total-1$ $f_j^C(x_j) = \sum_{k \in I_0^{N,d}} \hat{f}_k^C * cos(2 \pi k x_j)$

void nfct_adjoint ( nfct_plan * ths_plan )

executes a transposed NFCT (approximate,fast), computes for $k \in I_0^{N,d}$ $h^C(k) = \sum_{j \in I_0^{(M\_total,1)}} f_j^C * cos(2 \pi k x_j)$

void nfct_finalize ( nfct_plan * ths_plan )

Destroys a plan.