37 lines
1.2 KiB
C
37 lines
1.2 KiB
C
/*
|
|
* Copyright (c) 2019 Andri Yngvason
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
|
|
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
|
|
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
|
|
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
|
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
|
|
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
|
* PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <stdint.h>
|
|
|
|
/*
|
|
* This is an exponential smoothing filter with a time constant.
|
|
*
|
|
* The time constant must be set prior to applying the filter. It is, rougly
|
|
* speaking, the response time of the filter.
|
|
*
|
|
* See: https://en.wikipedia.org/wiki/Exponential_smoothing
|
|
*/
|
|
struct smooth {
|
|
double time_constant;
|
|
|
|
uint64_t last_time;
|
|
double last_result;
|
|
};
|
|
|
|
double smooth(struct smooth* self, double input);
|