/* bspline/gsl_bspline.h

 *

 * Copyright (C) 2006 Patrick Alken

 * Copyright (C) 2008 Rhys Ulerich

 *

 * 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 3 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.

 */

#ifndef __GSL_BSPLINE_H__

#define __GSL_BSPLINE_H__

#include <stdlib.h>

#include <gsl/gsl_math.h>

#include <gsl/gsl_vector.h>

#include <gsl/gsl_matrix.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

typedef struct

{

    size_t k;      /* spline order */

    size_t km1;    /* k - 1 (polynomial order) */

    size_t l;      /* number of polynomial pieces on interval */

    size_t nbreak; /* number of breakpoints (l + 1) */

    size_t n;      /* number of bspline basis functions (l + k - 1) */

    gsl_vector *knots;  /* knots vector */

    gsl_vector *deltal; /* left delta */

    gsl_vector *deltar; /* right delta */

    gsl_vector *B;      /* temporary spline results */

    /* bspline derivative parameters */

    gsl_matrix *A;      /* work matrix */

    gsl_matrix *dB;     /* temporary derivative results */

} gsl_bspline_workspace;

gsl_bspline_workspace *

gsl_bspline_alloc(const size_t k, const size_t nbreak);

void gsl_bspline_free(gsl_bspline_workspace *w);

size_t gsl_bspline_ncoeffs(gsl_bspline_workspace * w);

size_t gsl_bspline_order(gsl_bspline_workspace * w);

size_t gsl_bspline_nbreak(gsl_bspline_workspace * w);

double gsl_bspline_breakpoint(size_t i, gsl_bspline_workspace * w);

double gsl_bspline_greville_abscissa(size_t i, gsl_bspline_workspace *w);

int

gsl_bspline_knots(const gsl_vector *breakpts, gsl_bspline_workspace *w);

int gsl_bspline_knots_uniform(const double a, const double b,

                              gsl_bspline_workspace *w);

int

gsl_bspline_knots_greville(const gsl_vector *abscissae,

                           gsl_bspline_workspace *w,

                           double *abserr);

int

gsl_bspline_eval(const double x, gsl_vector *B, 

                 gsl_bspline_workspace *w);

int

gsl_bspline_eval_nonzero(const double x,

                         gsl_vector *Bk,

                         size_t *istart,

                         size_t *iend,

                         gsl_bspline_workspace *w);

int

gsl_bspline_deriv_eval(const double x,

                       const size_t nderiv,

                       gsl_matrix *dB,

                       gsl_bspline_workspace *w);

int

gsl_bspline_deriv_eval_nonzero(const double x,

                               const size_t nderiv,

                               gsl_matrix *dB,

                               size_t *istart,

                               size_t *iend,

                               gsl_bspline_workspace *w);

__END_DECLS

#endif /* __GSL_BSPLINE_H__ */