| /* dht/gsl_dht.h |
| * |
| * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at |
| * your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| /* Author: G. Jungman |
| */ |
| #ifndef __GSL_DHT_H__ |
| #define __GSL_DHT_H__ |
| |
| #undef __BEGIN_DECLS |
| #undef __END_DECLS |
| #ifdef __cplusplus |
| # define __BEGIN_DECLS extern "C" { |
| # define __END_DECLS } |
| #else |
| # define __BEGIN_DECLS /* empty */ |
| # define __END_DECLS /* empty */ |
| #endif |
| |
| __BEGIN_DECLS |
| |
| |
| struct gsl_dht_struct { |
| size_t size; /* size of the sample arrays to be transformed */ |
| double nu; /* Bessel function order */ |
| double xmax; /* the upper limit to the x-sampling domain */ |
| double kmax; /* the upper limit to the k-sampling domain */ |
| double * j; /* array of computed J_nu zeros, j_{nu,s} = j[s] */ |
| double * Jjj; /* transform numerator, J_nu(j_i j_m / j_N) */ |
| double * J2; /* transform denominator, J_{nu+1}^2(j_m) */ |
| }; |
| typedef struct gsl_dht_struct gsl_dht; |
| |
| |
| /* Create a new transform object for a given size |
| * sampling array on the domain [0, xmax]. |
| */ |
| gsl_dht * gsl_dht_alloc(size_t size); |
| gsl_dht * gsl_dht_new(size_t size, double nu, double xmax); |
| |
| /* Recalculate a transform object for given values of nu, xmax. |
| * You cannot change the size of the object since the internal |
| * allocation is reused. |
| */ |
| int gsl_dht_init(gsl_dht * t, double nu, double xmax); |
| |
| /* The n'th computed x sample point for a given transform. |
| * 0 <= n <= size-1 |
| */ |
| double gsl_dht_x_sample(const gsl_dht * t, int n); |
| |
| |
| /* The n'th computed k sample point for a given transform. |
| * 0 <= n <= size-1 |
| */ |
| double gsl_dht_k_sample(const gsl_dht * t, int n); |
| |
| |
| /* Free a transform object. |
| */ |
| void gsl_dht_free(gsl_dht * t); |
| |
| |
| /* Perform a transform on a sampled array. |
| * f_in[0] ... f_in[size-1] and similarly for f_out[] |
| */ |
| int gsl_dht_apply(const gsl_dht * t, double * f_in, double * f_out); |
| |
| |
| __END_DECLS |
| |
| #endif /* __GSL_DHT_H__ */ |
