/* filter/gsl_filter.h
*
* Copyright (C) 2018 Patrick Alken
*
* 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_FILTER_H__
#define __GSL_FILTER_H__
#include <gsl/gsl_math.h>
#include <gsl/gsl_vector.h>
#include <gsl/gsl_movstat.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
/* end point handling methods */
typedef enum
{
GSL_FILTER_END_PADZERO = GSL_MOVSTAT_END_PADZERO,
GSL_FILTER_END_PADVALUE = GSL_MOVSTAT_END_PADVALUE,
GSL_FILTER_END_TRUNCATE = GSL_MOVSTAT_END_TRUNCATE
} gsl_filter_end_t;
/* robust scale estimates */
typedef enum
{
GSL_FILTER_SCALE_MAD, /* median absolute deviation */
GSL_FILTER_SCALE_IQR, /* interquartile range */
GSL_FILTER_SCALE_SN, /* S_n scale statistic */
GSL_FILTER_SCALE_QN /* Q_n scale statistic */
} gsl_filter_scale_t;
/* workspace for Gaussian filter */
typedef struct
{
size_t K; /* window size */
double *kernel; /* Gaussian kernel, size K */
gsl_movstat_workspace *movstat_workspace_p;
} gsl_filter_gaussian_workspace;
gsl_filter_gaussian_workspace *gsl_filter_gaussian_alloc(const size_t K);
void gsl_filter_gaussian_free(gsl_filter_gaussian_workspace * w);
int gsl_filter_gaussian(const gsl_filter_end_t endtype, const double alpha, const size_t order, const gsl_vector * x,
gsl_vector * y, gsl_filter_gaussian_workspace * w);
int gsl_filter_gaussian_kernel(const double alpha, const size_t order, const int normalize, gsl_vector * kernel);
/* workspace for standard median filter */
typedef struct
{
gsl_movstat_workspace *movstat_workspace_p;
} gsl_filter_median_workspace;
gsl_filter_median_workspace *gsl_filter_median_alloc(const size_t K);
void gsl_filter_median_free(gsl_filter_median_workspace * w);
int gsl_filter_median(const gsl_filter_end_t endtype, const gsl_vector * x, gsl_vector * y, gsl_filter_median_workspace * w);
/* workspace for recursive median filter */
typedef struct
{
size_t H; /* window half-length (K / 2) */
size_t K; /* window size */
void *state; /* workspace for min/max accumulator */
double *window; /* array holding first window */
const gsl_movstat_accum * minmaxacc; /* minimum/maximum accumulator */
gsl_movstat_workspace *movstat_workspace_p;
} gsl_filter_rmedian_workspace;
gsl_filter_rmedian_workspace *gsl_filter_rmedian_alloc(const size_t K);
void gsl_filter_rmedian_free(gsl_filter_rmedian_workspace * w);
int gsl_filter_rmedian(const gsl_filter_end_t, const gsl_vector * x, gsl_vector * y, gsl_filter_rmedian_workspace * w);
int gsl_filter_rmedian2(const gsl_vector * x, gsl_vector * y, gsl_filter_rmedian_workspace * w);
typedef struct
{
gsl_movstat_workspace *movstat_workspace_p;
} gsl_filter_impulse_workspace;
gsl_filter_impulse_workspace *gsl_filter_impulse_alloc(const size_t K);
void gsl_filter_impulse_free(gsl_filter_impulse_workspace * w);
int gsl_filter_impulse(const gsl_filter_end_t endtype, const gsl_filter_scale_t scale_type, const double t,
const gsl_vector * x, gsl_vector * y, gsl_vector * xmedian, gsl_vector * xsigma, size_t * noutlier,
gsl_vector_int * ioutlier, gsl_filter_impulse_workspace * w);
__END_DECLS
#endif /* __GSL_FILTER_H__ */