hp_filter.h File Reference

#include "core.h"

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Go to the source code of this file.

Data Structures
struct	hp_filter_t

Functions
static void	hp_filter_init (hp_filter_t *filt, double f_cutoff)
static double	hp_filter_update (hp_filter_t *filt, double m, double d_t)
static double	hp_filter_get (const hp_filter_t *filt)
static void	hp_filter_set_f_cutoff (hp_filter_t *filt, double f_cutoff)
static double	hp_filter_get_f_cutoff (const hp_filter_t *filt)

Detailed Description

This module contains a header-implementation of a high-pass filter.

See also

hp_filter_t

hp_filter_init()

hp_filter_update()

Definition in file hp_filter.h.

Function Documentation

hp_filter_get()

static double hp_filter_get ( const hp_filter_t *  filt )

static

Returns

The current output of a high-pass filter without updating the filter's state.

Note

The filter needs at least 2 measurements before it can start providing valid output. The filter's output will be NAN before that.

See also

hp_filter_update()

Definition at line 113 of file hp_filter.h.

hp_filter_get_f_cutoff()

static double hp_filter_get_f_cutoff ( const hp_filter_t *  filt )

static

Returns

The current cutoff frequency (in Hz) for a high-pass filter.

Definition at line 136 of file hp_filter.h.

hp_filter_init()

static void hp_filter_init ( hp_filter_t *  filt, double  f_cutoff  )

static

Initializes a high-pass filter.

Parameters

filt	The filter to be initialized.
f_cutoff	Filter cutoff frequency in Hz.

See also

hp_filter_t

Definition at line 65 of file hp_filter.h.

hp_filter_set_f_cutoff()

static void hp_filter_set_f_cutoff ( hp_filter_t *  filt, double  f_cutoff  )

static

Sets a new cutoff frequency for a high-pass filter.

Parameters

filt	The filter for which to change the cutoff frequency.
f_cutoff	New cutoff frequency to set (in Hz).

Definition at line 125 of file hp_filter.h.

hp_filter_update()

static double hp_filter_update ( hp_filter_t *  filt, double  m, double  d_t  )

static

Updates a high-pass filter with a new input value. You want to call this every time a new measurement is obtained, which you want to filter.

Parameters

filt	The filter to be updated.
m	The new measurement to be integrated into the filter.
d_t	Delta-time in seconds since the last filter update.

Returns

The current filter output after the update has been performed.

Note

The filter needs at least 2 measurements before it can start providing valid output. The filter's output will be NAN before that.

See also

hp_filter_get()

Definition at line 88 of file hp_filter.h.