| /* cheb/gsl_chebyshev.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. |
| */ |
| |
| #ifndef __GSL_CHEBYSHEV_H__ |
| #define __GSL_CHEBYSHEV_H__ |
| |
| #include <gsl/gsl_math.h> |
| #include <gsl/gsl_mode.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 |
| |
| |
| /* data for a Chebyshev series over a given interval */ |
| |
| struct gsl_cheb_series_struct { |
| |
| double * c; /* coefficients */ |
| size_t order; /* order of expansion */ |
| double a; /* lower interval point */ |
| double b; /* upper interval point */ |
| |
| /* The following exists (mostly) for the benefit |
| * of the implementation. It is an effective single |
| * precision order, for use in single precision |
| * evaluation. Users can use it if they like, but |
| * only they know how to calculate it, since it is |
| * specific to the approximated function. By default, |
| * order_sp = order. |
| * It is used explicitly only by the gsl_cheb_eval_mode |
| * functions, which are not meant for casual use. |
| */ |
| size_t order_sp; |
| |
| /* Additional elements not used by specfunc */ |
| |
| double * f; /* function evaluated at chebyschev points */ |
| }; |
| typedef struct gsl_cheb_series_struct gsl_cheb_series; |
| |
| |
| /* Calculate a Chebyshev series of specified order over |
| * a specified interval, for a given function. |
| * Return 0 on failure. |
| */ |
| gsl_cheb_series * gsl_cheb_alloc(const size_t order); |
| |
| /* Free a Chebyshev series previously calculated with gsl_cheb_alloc(). |
| */ |
| void gsl_cheb_free(gsl_cheb_series * cs); |
| |
| /* Calculate a Chebyshev series using the storage provided. |
| * Uses the interval (a,b) and the order with which it |
| * was initially created. |
| * |
| */ |
| int gsl_cheb_init(gsl_cheb_series * cs, const gsl_function * func, |
| const double a, const double b); |
| |
| |
| /* Evaluate a Chebyshev series at a given point. |
| * No errors can occur for a struct obtained from gsl_cheb_new(). |
| */ |
| double gsl_cheb_eval(const gsl_cheb_series * cs, const double x); |
| int gsl_cheb_eval_err(const gsl_cheb_series * cs, const double x, |
| double * result, double * abserr); |
| |
| |
| /* Evaluate a Chebyshev series at a given point, to (at most) the given order. |
| * No errors can occur for a struct obtained from gsl_cheb_new(). |
| */ |
| double gsl_cheb_eval_n(const gsl_cheb_series * cs, const size_t order, |
| const double x); |
| int gsl_cheb_eval_n_err(const gsl_cheb_series * cs, const size_t order, |
| const double x, double * result, double * abserr); |
| |
| |
| /* Evaluate a Chebyshev series at a given point, using the default |
| * order for double precision mode(s) and the single precision |
| * order for other modes. |
| * No errors can occur for a struct obtained from gsl_cheb_new(). |
| */ |
| double gsl_cheb_eval_mode(const gsl_cheb_series * cs, const double x, gsl_mode_t mode); |
| int gsl_cheb_eval_mode_e(const gsl_cheb_series * cs, const double x, gsl_mode_t mode, double * result, double * abserr); |
| |
| |
| |
| /* Compute the derivative of a Chebyshev series. |
| */ |
| int gsl_cheb_calc_deriv(gsl_cheb_series * deriv, const gsl_cheb_series * cs); |
| |
| /* Compute the integral of a Chebyshev series. The |
| * integral is fixed by the condition that it equals zero at |
| * the left end-point, ie it is precisely |
| * Integrate[cs(t; a,b), {t, a, x}] |
| */ |
| int gsl_cheb_calc_integ(gsl_cheb_series * integ, const gsl_cheb_series * cs); |
| |
| |
| |
| |
| __END_DECLS |
| |
| #endif /* __GSL_CHEBYSHEV_H__ */ |